1
general::
A word used to deprive a statement of its force or evade a direct commitment, as in Calling it "organized spontaneity" is using a weasel word; "organized" has sucked the meaning out of "spontaneity.'' This idiom may allude to the weasel's habit of sucking the contents out of a bird's egg, so that only the shell remains. [Late 1800s]
American Heritage Idioms