engaged in or accustomed to close observation; caught by a couple of alert cops; alert enough to spot the opportunity when it came; constantly alert and vigilant, like a sentinel on duty

[ Syn: alert ]

experiencing or accompanied by sleeplessness; insomniac old people; insomniac nights; lay sleepless all night; twenty watchful, weary, tedious nights- Shakespeare

[ Syn: insomniac , sleepless ]