1. any of the categories into which a psychiatric syndrome can be classified in terms of its predominant symptoms. For example, Adolf Meyer distinguished affective, delirious, deteriorated, disguised-conflict, organic, and paranoid reaction types. See schizophrenic reaction.

2. in reaction-time experiments, a particular type of set, or readiness of the participant or participants: motor (prepared to respond), sensory (prepared to receive a stimulus), or mixed.