'impurity', loathsomeness, foulness. -
In Vis.M. VI, it is the cemetery contemplations (sīvathika) that are called 'meditation-subjects of impurity' (asubha-kammatthāna; s. bhāvanā).
In the Girimananda Sutta (A. X., 50), however, the perception of impurity (asubha-saññā) refers to the contemplation of the 32 parts of the body (s. kāya-gatā-sati).
The contemplation of the body's impurity is an antidote against the hindrance of sense-desire (s. nīvarana) and the mental perversion (vipallāsa) which sees what is truly impure as pure and beautiful.