Prepared, on one's guard, watchful, vigilant, cautious, alert. Cf. aware, adj. 1. Now archaic.

figurative. Of the mind: Uplifted, directed upwards; alert, attentive. Obsolete.

Having the mind, thought, etc., focused on or closely engaged with what one is doing; attentive, alert, aware (opposed to absent, adj. 4); prompt to…

Listening attentively; attentive, alert.

Perceptive; characterized by perceptiveness.

Having an upward direction. Of the eyes, face, etc.: Uplifted. Of motion: Directed upwards. figurative. Of the mind: Active, attentive. Obsolete.

Set upright, pricked up (as the ears of a beast); having the faculties directed towards; figurative intent, attentive, on the alert.

Originally Military. Engaged in close observation of a situation or event, one's surroundings, etc… In attributive use.

slang (originally and chiefly British). Aware of or possessing knowledge about something, esp. illicit or criminal activity; alert; suspicious. Also…

figurative. colloquial. Thoroughly vigilant or on the alert; fully aware of what is going on, or of what it is best to do; intellectually keen…

Originally U.S. Nautical. Watchful, alert, vigilant. Chiefly in phrases such as to keep a bright lookout, to keep a bright eye on, etc.

Observant, disposed to notice things.

Handy, clever, wide-awake. rare.

(un-, prefix1 affix 1.)

Quick, sharp; alert, energetic; wary, wide awake; rising early.