不得

must not / may not / not to be allowed / cannot

no; not so / (bound form) not; un-

to obtain / to get / to gain / to catch (a disease) / proper / suitable / proud / contented / to allow / to permit / ready / finished

structural particle: used after a verb (or adjective as main verb), linking it to following phrase indicating effect, degree, possibility etc

to have to / must / ought to / to need to

have no choice or option but to / cannot but / have to / can't help it / can't avoid

desperately serious / disastrous / extremely / exceedingly

to act against one's will / to have no alternative but to / to have to / to have no choice / must

to have no other choice / to be the last resort

not to enjoy popular support / to be unpopular

awkward / unhandy / be indisposed / not feel well

to be unable to get into (a house, an organization, a field of study, a particular type of career etc)

too uncouth to appear in public (idiom) / unfit for a public role

to be unable to get in / to fail to find a proper approach to handling sth

only when absolutely essential (idiom); as a last resort

(idiom) lacking in social grace and unfit to be a representative