(a.) Of or pertaining to the act or power of perceiving; having the faculty or power of perceiving; used in perception.

acute alert alive alive to all-knowing apperceptive appercipient apprehending apprehensive argute astute attentive aware cogent cognizant comprehending conscious discerning farseeing farsighted foreseeing foresighted forethoughted forethoughtful gnostic impressible impressionable impressive incisive insightful intelligent judicious keen knowing knowledgeable longheaded longsighted mindful observant omniscient on the ball penetrating percipient perspicacious perspicuous piercing prehensile prehensive provident quick quick-witted receptive responsive sagacious sage sensible sensile sensitive sensitive to sentient sharp shrewd sophic susceptible susceptive trenchant understanding wise