crisp, sharp -- ((of something seen or heard) clearly defined; "a sharp photographic image"; "the sharp crack of a twig"; "the crisp snap of dry leaves underfoot")
acute, discriminating, incisive, keen, knifelike, penetrating, penetrative, piercing, sharp -- (having or demonstrating ability to recognize or draw fine distinctions; "an acute observer of politics and politicians"; "incisive comments"; "icy knifelike reasoning"; "as sharp and incisive as the stroke of a fang"; "penetrating insight"; "frequent penetrative observations")
astute, sharp, shrewd -- (marked by practical hardheaded intelligence; "a smart businessman"; "an astute tenant always reads the small print in a lease"; "he was too shrewd to go along with them on a road that could lead only to their overthrow")
sharp, sharp-worded, tart -- (harsh; "sharp criticism"; "a sharp-worded exchange"; "a tart remark")
shrill, sharp -- (having or emitting a high-pitched and sharp tone or tones ; "a shrill whistle"; "a shrill gaiety")
abrupt, precipitous, sharp -- (extremely steep; "an abrupt canyon"; "the precipitous rapids of the upper river"; "the precipitous hills of Chinese paintings"; "a sharp drop")
sharp -- (keenly and painfully felt; as if caused by a sharp edge or point; "a sharp pain"; "sharp winds")
sharp -- (having or made by a thin edge or sharp point; suitable for cutting or piercing; "a sharp knife"; "a pencil with a sharp point")
sharp -- ((of a musical note) raised in pitch by one chromatic semitone; "C sharp")
sharp -- (very sudden and in great amount or degree; "a sharp drop in the stock market")