sharp (adj.)

Old English scearp "having a cutting edge; pointed; intellectually acute, active, shrewd; keen (of senses); severe; biting, bitter (of tastes)," from Proto-Germanic *skarpaz, literally "cutting" (source also of Old Saxon scarp, Old Norse skarpr, Old Frisian skerp, Dutch scherp, German scharf "sharp"), from PIE root *sker- (1) "to cut" (source also of Lettish skarbs "sharp," Middle Irish cerb "cutting").

The figurative meaning "acute or penetrating in intellect or perception" was in Old English; hence "keenly alive to one's own interests, quick to take advantage" (1690s). Of words or talk, "cutting, sarcastic," from early 13c. Meaning "distinct in contour" is from 1670s. The adverbial meaning "abruptly" is from 1836; that of "promptly" is first attested 1840. The musical meaning "half step above (a given tone)" is from 1570s. Meaning "stylish" is from 1944, hepster slang, from earlier general slang sense of "excellent" (1940). Phrase sharp as a tack first recorded 1912 (sharp as a needle has been around since Old English). Sharp-shinned attested from 1704 of persons, 1813 of hawks.

sharp (n.)

"a cheat at games," 1797, short for sharper (1680s) in this sense. Meaning "expert, connoisseur" is attested from 1840, and likely is from sharp (adj.). Music sense is from 1570s. The noun was used 14c. as "a sharp weapon, edge of a sword."

Definitions of sharp
sharp (adj.)
(of something seen or heard) clearly defined;
the sharp crack of a twig
a sharp photographic image
Synonyms: crisp
sharp (adj.)
ending in a sharp point;
Synonyms: acuate / acute / needlelike
sharp (adj.)
having or demonstrating ability to recognize or draw fine distinctions;
as sharp and incisive as the stroke of a fang
Synonyms: acute / discriminating / incisive / keen / knifelike / penetrating / penetrative / piercing
sharp (adj.)
marked by practical hardheaded intelligence;
Synonyms: astute / shrewd
sharp (adj.)
sharp criticism
a sharp-worded exchange
Synonyms: sharp-worded / tart
sharp (adj.)
having or emitting a high-pitched and sharp tone or tones;
Synonyms: shrill
sharp (adj.)
extremely steep;
a sharp drop
Synonyms: abrupt / precipitous
sharp (adj.)
keenly and painfully felt; as if caused by a sharp edge or point;
a sharp pain
sharp winds
sharp (adj.)
having or made by a thin edge or sharp point; suitable for cutting or piercing;
a pencil with a sharp point
a sharp knife
sharp (adj.)
(of a musical note) raised in pitch by one chromatic semitone;
C sharp
sharp (adj.)
very sudden and in great amount or degree;
a sharp drop in the stock market
sharp (adj.)
quick and forceful;
a sharp blow
sharp (n.)
a musical notation indicating one half step higher than the note named;
sharp (n.)
a long thin sewing needle with a sharp point;
sharp (adv.)
changing suddenly in direction and degree;
turn sharp left here
Synonyms: sharply / acutely