What are some synonyms for must?

Main Entry: must Part of Speech: noun Definition: necessity, essential Synonyms: charge, commitment, condition, duty, fundamental, imperative, necessary, need, obligation, prerequisite, requirement, requisite, right, committal, devoir, ought, precondition, sine qua non Main Entry: must Part of Speech: verb Definition: ought, should Synonyms: be compelled, be destined, be directed, be doomed, be driven, be made, be necessitated, be obliged, be one's fate, be ordered, be required, got to, have, have got to, have no choice, have to, must needs, need, pushed to the wall