Meaning of “unlikely” - Learner’s Dictionary

unlikely

adjective uk us /ʌnˈlaɪkli/
NOT HAPPEN

B1 not expected to happen:

[ + (that) ] It's unlikely that I'll be able to come to the party.
[ + to do sth ] He's unlikely to arrive before midday.
NOT TRUE

probably not true:

an unlikely explanation

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