1
general::
Halt something at an early stage, or thoroughly check something. For example, By arresting all the leaders, they nipped the rebellion in the bud. This metaphoric expression, alluding to a spring frost that kills flower buds, was first recorded in a Beaumont and Fletcher play of 1606-1607.
American Heritage Idioms
2
general::
Phrase(s): nip something in the bud
Fig. to put an end to something before it develops into something larger. (Alludes to destroying a flower bud before it blooms.) • I wanted to nip that little romance in the bud. • The whole idea was nipped in the bud.
McGrawhill's American Idioms And Phrasal Verbs