Meaning of “streak” - Learner’s Dictionary

streak

noun [ C ] uk us /striːk/
MARK

a thin line or mark:

She has a streak of white hair.
QUALITY

a quality in someone's character, especially a bad one:

Tom has a mean/ruthless streak.
a winning/losing streak

a period of always winning/losing a game:

I'm on a winning streak.

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