noun
cheating; foul play; sneaky act
Refers to dishonest or underhanded behavior, often in games, exams, or everyday situations. Can be used as a noun or in the phrase ずるをする.
テストでずるをしてはいけません。
You must not cheat on the test.
彼はゲームでずるばかりする。
He always cheats in games.
noun
cheater; sly person; cunning fellow
Used to describe a person who habitually cheats or acts slyly. Often used in a derogatory or teasing way.
あいつは本当にずるだな。
That guy is such a cheat.
The origin is uncertain, but it may be related to the adjective ずるい (sly). The word is colloquial and primarily used in spoken Japanese.