Meaning of “fling” - Learner’s Dictionary

fling

noun [ C ] uk us /flɪŋ/
RELATIONSHIP

a sexual relationship that is short and not serious:

She had a fling with someone last summer.
ENJOYMENT

a short period of time when you have a lot of enjoyment or pleasure:

This is my last fling before the exams.

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