The Collaborative International Dictionary
Look sharp
Sharp \Sharp\, adv.
-
To a point or edge; piercingly; eagerly; sharply.
--M. Arnold.The head [of a spear] full sharp yground.
--Chaucer.You bite so sharp at reasons.
--Shak. -
Precisely; exactly; as, we shall start at ten o'clock sharp. [Colloq.]
Look sharp, attend; be alert. [Colloq.]
Wiktionary
look sharp
vb. Pay attention; be alert.