Quick to notice; showing quick and keen perception.

synonym: observant.

Roget 457: attentive, mindful, observant, regardful; alive to, awake to; observing etc. v.; alert, open-eyed; intent on, taken up with, occupied with, engaged in; engrossed in, wrapped in, absorbed, rapt, transfixed, riveted, mesmerized, hypnotized; glued to (the TV, the window, a book); breathless; preoccupied etc. (inattentive) 458; watchful etc. (careful) 459; breathless, undistracted, upon the stretch; on the watch etc. (expectant) 507.    steadfast.    [compelling attention] interesting, engrossing, mesmerizing, riveting.    ... show more