Meaning of “otherwise” - Learner’s Dictionary

otherwise

conjunction uk us /ˈʌðəwaɪz/

B1 used when saying what will happen if someone does not obey an order or do what has been suggested:

You'd better phone home, otherwise your parents will start to worry.
He ought to pay the fine, otherwise he might go to prison.

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