To butt, strike against; contact. sparśa, touch, contact, collision, the quality of tangibility, feeling, sensation. M.W. Eleven kinds of sensation are given— hot, cold, hard, soft, etc. sparśa is one of the twelve nidānas, cf. 十二因緣, and of the sadāyatana, cf. 六入. It is also used with the meaning of 濁 unclean.

A Dictionary of Chinese Buddhist Terms, William Edward Soothill and Lewis Hodous

sparśa

(Sanskrit; Pāli, phassa; contact). Technical term in Buddhist psychology referring to the contact between an organ of sense, such as the eye, and its corresponding object, such as a visible form. In an intact organism, the contact between the two gives rise to a particular kind of consciousness (vijñāna), for example, eye-consciousness or the experience of seeing (cakṣu-vijñāna), ear consciousness or the experience of hearing (śrota-vijñāna), etc. Sparśa thus denotes the moment when the mind makes contact with the external world. This experience can trigger off a chain of either wholesome or unwholesome mental states (for example, the perception of a pleasant form may lead to desire and craving (tṛṣṇā) for the object perceived. Buddhist psychology emphasizes the need for constant mindfulness (smṛti) in order to monitor—and when necessary interrupt—negative chains of consciousness which may follow an initial sensory contact. The function of sparśa is illustrated by its position in the twelvefold scheme of Dependent Origination (pratītya-samutpāda): as the sixth link, it arises in dependence on the six sense-bases (ṣad-āyatana) and conditions feeling (vedanā). Sparśa is also one of the four nutriments (āhāra).

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

Contact, touch

Sarvastivada Abhidharma, Sanskrit-English Glossary, by Bhikkhu KL Dhammajoti