go off — Phrasal Verb with go /gəʊ/ verb [I] (present participle going, past tense went, past participle gone)
LEAVE › to leave a place and go somewhere else: She's gone off to the pub with Tony.
FOOD UK informal › If food goes off, it is not good to eat any more because it is too old.
STOP › If a light or machine goes off, it stops working: The heating goes off at 10 o'clock.
EXPLODE › If a bomb or gun goes off, it explodes or fires.
MAKE NOISE › If something that makes a noise goes off, it suddenly starts making a noise: His car alarm goes off every time it rains.
go off on one informal › to react angrily to something