noun
stupid brat; little shit; son of a bitch
Vulgar, derogatory term for a child or young person, expressing strong anger or contempt. Often used as an insult or exclamation.
あのクソガキ、また窓を割った!
That little shit broke the window again!
クソガキどもがうるさくてかなわない。
Those damn brats are so noisy I can't stand it.
Compound of クソ (kuso, 'shit/damn', a vulgar intensifier) and ガキ (gaki, 'brat', from 餓鬼, originally a Buddhist term for a hungry ghost, later used for children). The exact derivation is uncertain, but the combination is a straightforward vulgar insult.