The phrase "puts one's tail between legs" is an idiom that means to show fear, shame or embarrassment. It is commonly used to describe a situation where someone has been defeated or outwitted. There are several synonyms for this phrase, including "bows out," "concedes defeat," "submits," "capitulates," "backs down," "surrenders," "recedes," "retreats," "acquiesces," "yields," and "gives way." Each of these synonyms carries a similar meaning and can be used interchangeably in most situations. However, it is important to choose the most appropriate synonym based on the context in which it is used.