Definitions for smart aleckˈæl ɪk
Random House Webster's College Dictionary
smart′ al`eckˈæl ɪk(n.)
(or al`ec )
an obnoxiously conceited and impertinent person.
Origin of smart aleck:
1860–65, Amer.; generic use of Aleck, nickname for Alexander
wise guy, smart aleck, wiseacre, wisenheimer, weisenheimer(noun)
an upstart who makes conceited, sardonic, insolent comments
One who is given to obnoxious or insolent humor; a wise guy.
One who is pretentious about their own cleverness or knowledge; a know-it-all.
One who is obnoxiously self-assured; a show off.
A well-dressed person.
Origin: Aleck is a nickname for Alexander. The phrase "smart aleck" is possibly derived from the name Aleck Hoag, a 19 century con man and thief. A conceited know-it-all, dates back to mid-19th century America. Alec Hoag was a notorious pimp and thief who operated in New York in the 1840s. He operated a trick called "The Panel Game" where he would sneak in via gaps in the walls and steal the valuables of his sleeping or unwary clients. The reputation he generated for not getting caught earned him the nickname Smart Alec.