needs must
archaic

• It is or was necessary or unavoidable.

  More example sentences

  • ‘if needs must, they will eat any food’
needs must do something
archaic

• Cannot avoid or help doing something.

  More example sentences

  • ‘they must needs depart’
needs must when the Devil drives
proverb

• Sometimes you have to do something you would rather not.

Old English nēdes(see need, -s).