Meaning of “otherwise” - Learner’s Dictionary

otherwise

conjunction us uk /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.

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