tail between one's legs. Humiliated, in disgrace, fearful.

This is a direct translation of the gesture a dog makes to communicate humiliation and fear to other dogs and humans. While humans do not have tails per se, this gesture is readily seen across the species line, hence its easy application to humans.

So clear is the reference that it easily crosses at least some language and cultural boundaries. After the 2005 Summit of the Americas in Mar del Plata, Argentina, Venezuelan President Hugo Chavez was brimming with dog metaphors. In his November 13 television and radio address, he called Mexico President Vicente Fox the “perrito” or puppy dog of the U.S. Later he described President George Bush as having left the Summit “con el rabo entre las piernas”—that is, with the tail between the legs, having tried to defend the indefensible: the proposed Free Trade Area of the Americas.