1
general::
Back out of a situation or commitment, especially in a sneaky way. For example, I'd love to weasel out of serving on the board. This expression alludes to the stealthy hunting and nesting habits of the weasel, a small, slender-bodied predator. [Colloquial; mid-1900s]
American Heritage Idioms
2
general::
Phrase(s): weasel out (of something)
1. Fig. to squeeze one’s way out of something. • Somehow, the child managed to weasel out of the hole she was stuck in. • The mouse tried to weasel out. 2. Fig. to evade or avoid a job or responsibility. (Fig. on Q.) • Don’t try to weasel out of your responsibility! • You can’t weasel out! You have to do it.
McGrawhill's American Idioms And Phrasal Verbs