upādāna-kkhandha: the 5 'groups of clinging', or more clearly stated in accordance with Vis.M., 'the 5 groups of existence which form the objects of clinging'. Cf. M. 44, and see khandha.

Buddhist Dictionary, Manual of Buddhist Terms and Doctrines, by NYANATILOKA MAHATHERA

upādāna-skandha

(Sanskrit). The ‘aggregates of attachment’, or the five aggregates (skandha) seen as the source or the object of grasping (upādāna). The final part of the first Noble Truth (see Four Noble Truths) states that ‘the five aggregates of attachment are suffering’ (duḥkha). This means both that suffering is intrinsic to embodied existence, and that such existence itself leads to grasping after pleasurable sensations, generating an endless cycle of suffering in saṃsāra.

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