1. in cognitive psychology, the effect in which recent experience of a stimulus facilitates or inhibits later processing of the same or a similar stimulus. In repetition priming, presentation of a particular sensory stimulus increases the likelihood that participants will identify the same or a similar stimulus later in the test. In semantic priming, presentation of a word or sign influences the way in which participants interpret a subsequent word or sign.

2. in animal behavior, the ability of a pheromone to gradually alter the behavior of another member of the same species. —prime vb.