Meaning of “spoil” - Learner’s Dictionary

spoil

verb uk us /spɔɪl/ (past tense and past participle spoiled, spoilt)
MAKE BAD [ T ]

B1 to stop something from being enjoyable or successful:

The picnic was spoiled by the bad weather.
I don't want to spoil the fun, but could you turn the music down a bit?
CHILD [ T ]

If you spoil a child, you let them have anything they want or do anything they want, usually making them badly behaved.

TREAT WELL [ T ]

to treat someone very well, buying them things or doing things for them:

He's always sending flowers - he absolutely spoils me!
FOOD [ I ] formal

If food spoils, it starts to decay and you cannot eat it.

(Definition of “spoil” from the Cambridge Learner’s Dictionary © Cambridge University Press)