ajahn (Thai): Literally, “teacher.” From the Pāli word ācariya; often used in monasteries as a title for senior monks or nuns who have been ordained for ten years or more.

anagārika: Literally, “homeless one.” An eight-precept male postulant who often lives with bhikkhus and, in addition to his own meditation practice, also helps with certain services that are forbidden for bhikkhus to do, such as, using money, cutting plants, or cooking food.

anattā: Not-self, ownerless, impersonal.

anicca: Impermanent, inconstant, unsteady. Ajahn Chah often translated it as “not sure.”

asubha: Unattractive, not-beautiful. The Buddha recommended contemplation of this aspect of the body as an antidote to desire, lust, and complacency.

bhikkhu: A Buddhist monk; a man who has given up the householder’s life to join the monastic Saṅgha. He follows the Dhamma-Vinaya (the doctrine and discipline), the teachings of the Buddha as well as the Buddha’s established code of conduct.

brahmavihāra: The four sublime or divine abodes that are attained through the development of mettā, karuṇā, muditā, and upekkhā (boundless loving-kindness, compassion, sympathetic joy, and equanimity).

Buddha: The historical religious leader and teacher who lived around 2500 BCE in the Ganges Valley of India. After his enlightenment, he established a monks’, nuns’, and lay community under the instruction of what he called the Dhamma-Vinaya—the doctrine and discipline. The word Buddha literally means “awakened one” or “enlightened one.”

defilements: Impurities, vices. Unwholesome mental tendencies or inclinations that cloud the mind. In their most basic forms they are greed, hatred, and delusion.

Dhamma (Sanskrit: Dharma): In general, a spiritual or philosophical teaching describing the natural state of reality. When used in this book, Dhamma specifically refers to the teachings of the Buddha: a systematic understanding of suffering, its cause, and how one applies oneself to eliminate this suffering, thus ending the cycle of rebirth.

dhamma: Used as a term to define natural phenomena of the world, including phenomena of the mind.

Dhamma-Vinaya: The Doctrine and Discipline. The name the Buddha gave to the religion he founded. The conjunction of the Dhamma with the Vinaya forms the core of the Buddhist religion.

dukkha: “Hard to bear,” unsatisfactoriness, suffering, stress.

Eightfold Path: See Noble Eightfold Path.

Forest Tradition: The tradition of Buddhist monks and nuns who have primarily dwelled in forests emphasizing formal meditation practice and following the Buddha’s monastic code of conduct (Vinaya).

Four Noble Truths: The first and central teaching of the Buddha about dukkha, its origin, cessation, and the path leading toward its cessation. Complete understanding of the Four Noble Truths is equivalent to the realization of Nibbāna.

kamma (Sanskrit karma): Volitional action by means of body, speech, or mind. Kamma always leads to an effect (kamma-vipāka).

Kaṭhina: A traditional cloth offering ceremony held at the end of the annual Rains Retreat celebrating community harmony.

khandhas (Sanskrit skandha): Heap, group, aggregate. Physical and mental components of the personality and of sensory experience in general. The five bases of clinging: form, feeling, perception, mental formations, and consciousness.

kuṭi: A small dwelling place for a Buddhist monastic; a hut.

Luang Por (Thai): Venerable Father, Respected Father; a friendly and reverential term of address used for elderly monks.

Māra: Evil, craving, and death personified as a deity, but also used as a representation of these elements within the mind.

mettā: Loving-kindness, goodwill, friendliness. One of the four brahmavihāras or sublime abodes.

Middle Way: The path the Buddha taught between the extremes of asceticism and sensual pleasure.

mindfulness: See sati.

Nibbāna (Sanskrit Nirvāṇa): Final liberation from all suffering, the goal of Buddhist practice. The liberation of the mind from the mental effluents, defilements, the round of rebirth, and from all that can be described or defined. As this term also denotes the extinguishing of a fire, it carries the connotations of stilling, cooling, and peace.

Noble Eightfold Path: Eight factors of spiritual practice leading to the cessation of suffering: right view, right intention, right speech, right action, right livelihood, right effort, right mindfulness, and right concentration.

Observance Day (Thai: Wan Phra): Once a week in Thai monasteries, monks and lay people set aside work duties and devote their time for a day (and sometimes all night) to formal practice. If the practice is continued until dawn the next day, the monks and laity will often refrain from lying down until dawn.

Pāli: An ancient Indian language related to Sanskrit. The teachings of the Theravada school of Buddhism were transmitted orally in Pāli for hundreds of years before being written down at the beginning of the Common Era in Sri Lanka.

Pāli Canon: The standardized collection of Theravada Buddhist suttas written in the Pāli language.

paññā: Wisdom, discernment, insight, intelligence, common sense, ingenuity. One of the ten perfections.

pāramī (Sanskrit: pāramitā): Perfection of the character. A group of ten qualities developed over many lifetimes: generosity, virtue, renunciation, discernment, energy/persistence, patience or forbearance, truthfulness, determination, goodwill, and equanimity.

paritta: Literally, “protection.” Auspicious blessing and protective chants typically recited by monastics and sometimes lay followers as well.

pūjā: Literally, “offering.” Chanting in various languages typically recited in the morning and evening by monastic and lay followers of a particular teacher, in this case the Buddha. Typically these recitations pay homage to the Buddha, Dhamma, and Saṅgha.

Rains Retreat (Vassa): The traditional time of year that monks and nuns determine to stay in one location for three months. Some monastics will take this time to intensify their formal or allowable ascetic practices. Monks and nuns will refer to themselves as having a certain number of Rains Retreats which signifies how many years they have been in robes.

right effort: One factor of the Eightfold Path which describes how a practitioner endeavors to prevent or abandon unwholesome qualities as well as maintain and develop wholesome qualities within the mind.

right speech: One factor of the Eightfold Path describing the proper use of speech: refraining from lying, divisive speech, abusive speech, and idle chatter.

right view: The first factor of the Eightfold Path. Right view is seeing experience in terms of Dhamma. This requires an understanding of kamma—that there are wholesome actions, unwholesome actions, and results of those actions. In the highest or noble sense, to have right view means to completely understand the Four Noble Truths.

samādhi: Concentration, one-pointedness of mind, mental stability. A state of concentrated calm resulting from meditation practice.

sampajañña: Clear comprehension, self-awareness, self-recollection, alertness.

saṃsāra: Literally, “perpetual wandering.” The cyclical wheel of existence. The continuous process of being born, growing old, suffering and dying again and again, the world of all conditioned phenomena, mental and material.

Saṅgha: This term is used to conventionally describe the community of ordained monks and nuns practicing the teachings of the Buddha. However, from a noble or ideal view, it specifically describes the followers of the Buddha, lay or ordained, who have realized one of the four levels of awakening: stream-entry, once-returning, non-returning, or Nibbāna.

saṅkhāra: Formation, compound, fabrication; the forces and factors that form things (physical or mental), the process of forming, and the formed things that result. Saṅkhāra can refer to anything formed by conditions, including thought-formations within the mind.

sati: Mindfulness, self-collectedness, recollection, bringing to mind. In some contexts, the word sati when used alone refers to clear-comprehension (sampajañña) as well.

sīla: Virtue, morality. The quality of ethical and moral purity that prevents one from engaging in unskillful actions. Also, the training precepts that restrain one from performing unskillful actions.

five spiritual faculties (pañca indriya): Faith, energy, mindfulness, concentration, and wisdom.

sutta (Sanskrit sūtra): Literally, “thread.” A discourse or sermon by the Buddha or his contemporary disciples. After the Buddha’s death the suttas were passed down in the Pāli language according to a well established oral tradition and finally committed to written form in Sri Lanka just around the turn of the common era. The Pāli suttas are widely regarded as the earliest record of the Buddha’s teachings.

taints (āsava): Mental effluents, fermentations, or outflows. Four qualities that taint the mind are sensuality, views, becoming, and ignorance.

Triple Gem: The Threefold Refuge: the Buddha, Dhamma, and Saṅgha.

tudong (Thai): The practice of wandering in the country and living on alms food.

Upāsikā Day: A day for Abhayagiri lay devotees to visit the monastery and partake in an afternoon teaching.

Vinaya: The Buddhist monastic discipline or code of conduct. The literal meaning of Vinaya is “leading out,” because maintenance of these rules leads out of unskillful states of mind. The Vinaya rules and traditions define every aspect of the bhikkhus’ and bhikkhunīs’ way of life.

Visuddhimagga: A post-canonical collection compiled by the Bhikkhu Bhadantācariya Buddhaghosa in the fifth century. It is a treatise explaining in detail the path of purification.

wat (Thai): A monastery.