Āsava is a Pali term (Sanskrit: Āsrava) that is used in Buddhist scripture, philosophy, and psychology, meaning "influx, canker."
It refers to the mental defilements of sensual pleasures, craving for existence, and ignorance, which perpetuate samsara, the beginningless cycle of rebirth, dukkha, and dying again.
Scholars differ as to whether the flow implied by the prefix ā is inward or outward; hence some have rendered it as "influxes" or "influences," others as "outflows" or "effluents.
[4]Bhikkhu Bodhi: A stock passage in the suttas indicates the term's real significance independently of etymology when it describes the āsavas as states "that defile, bring renewal of existence, give trouble, ripen in suffering, and lead to future birth, aging and death" (MN 36.47; I 250).
These figurative meanings perhaps describe facets of the concept of āsava: kept long in storage, oozing out, taint, corroding, etc.