expression, godan verb (-ru)
act annoyed; feel annoyed
Slang derived from うざい (annoying). Describes someone showing or feeling irritation, often in a whiny or exaggerated way. Used for both outward behavior and internal feeling.
彼はすぐウザがるから、話しかけにくい。
He gets annoyed so easily that it's hard to talk to him.
ちょっと注意しただけでウザがられた。
I just gave a little warning and they acted all annoyed.
Derived from the slang adjective うざい (annoying), itself a shortening of うざったい, with the verb-forming suffix ～がる added to express feeling or acting in a certain way.