sharp
noun
a musical notation indicating one half step higher than the note named
a long thin sewing needle with a sharp point
adjective
(of something seen or heard) clearly defined
“a sharp photographic image”
“the sharp crack of a twig”
Synonymscrispending in a sharp point
having or demonstrating ability to recognize or draw fine distinctions
“an acute observer of politics and politicians”
“incisive comments”
marked by practical hardheaded intelligence
“a smart businessman”
“an astute tenant always reads the small print in a lease”
harsh
“sharp criticism”
“a sharp-worded exchange”
having or emitting a high-pitched and sharp tone or tones
“a shrill whistle”
“a shrill gaiety”
Synonymsshrillextremely steep
“an abrupt canyon”
“the precipitous rapids of the upper river”
keenly and painfully felt; as if caused by a sharp edge or point
“a sharp pain”
“sharp winds”
Oppositesdullhaving or made by a thin edge or sharp point; suitable for cutting or piercing
“a sharp knife”
“a pencil with a sharp point”
Oppositesdull(of a musical note) raised in pitch by one chromatic semitone
“C sharp”
very sudden and in great amount or degree
“a sharp drop in the stock market”
quick and forceful
“a sharp blow”
adverb
changing suddenly in direction and degree
“the road twists sharply after the light”
“turn sharp left here”
Source: WordNet 3.1, Princeton University