ascetic, asceticism. By the time of the Buddha asceticism was a well-established feature of the Indian religious tradition, deriving from the ancient Vedic (see Veda) practice of austerities or tapas (‘heating’ or ‘burning’). In several discourses the Buddha describes and criticizes the many and varied practices of contemporary groups. Many went naked while others wore garments of cloth, hemp, rags, or hair. Some imitated the behaviour of animals and slept on the ground or on beds of thorns. Many restricted the type of food they would eat, the frequency of consumption, and the type of person they would accept it from. These ascetic practices were also being supplemented by the more sophisticated psycho-physical techniques of yoga. Although the Buddha prohibited extreme practices of this kind he allowed thirteen optional practices (dhutanga) of a moderately ascetic kind but resisted an attempt to make five of them compulsory for monks.

In the early stages of his quest for enlightenment (bodhi) the Buddha experimented with both yogic and ascetic practices and described his experience with two particular methods. The first involved retention of the breath for long periods of time but resulted only in a violent headache. The second was fasting, which he pursued until his body became emaciated and he later describes his appearance in this condition as follows: ‘All my limbs became like the joints of withered creepers…my gaunt ribs became like the crazy rafters of a tumble-down shed my scalp became shrivelled and shrunk and the skin of my belly clung to my backbone.’ A famous sculpture in the Lahore Museum depicts the Buddha in this wretched state. Renouncing these practices as counterproductive the Buddha took food once again and realized the importance of a harmonious relationship between mind and body in the pursuit of the religious life. He had now experienced both the extremes of a life of ease and comfort (as a prince) and the life of extreme austerity and asceticism. Neither was satisfactory and the Buddha finally chose the ‘middle way’ (madhyamā-pratipad) between the two as the only sure path to liberation which he then quickly gained. Thus his own personal experience became central to the formation of Buddhist views regarding extreme attitudes and practices of all kinds, and extreme asceticism thereafter found no real foothold in the tradition.  

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)

ascetic : (adj.; m.) tāpasa; muni; yati; isi; samaṇa.  

A.P. Buddhadatta Mahathera, Concise Pali-English and English-Pali Dictionary [available as digital version from Metta Net, Sri Lanka]