noun

1. (an) inborn tendency to behave in a way characteristic of a species; natural, unlearned, predictable response to stimuli suckling is an instinct in mammals
2. a natural or acquired tendency, aptitude, or talent; bent; knack; gift an instinct for doing the right thing
3. Psychoanalysis a primal psychic force or drive, as fear, love, or anger; specif., in Freudian analysis, either the life instinct (Eros) or the death instinct (Thanatos)

Etymology: < L instinctus, pp. of instinguere, to impel, instigate < in-, in + *stinguere, to prick: for IE base see stick

adjective