"Blencher" is a rarely used word, and hence, finding its synonyms can be an arduous task. However, some of the possible synonyms for this word are "chicken out," "shirk," "evade," "flinch," "waver," "back down," "withdraw," "retreat," "disengage," "recoil," "shy away," "shrink," etc. All of these words imply a sense of hesitation, avoidance, or fear, which can be associated with the act of "blenching." While some of these words may be more commonly used than "blencher," they all convey a similar meaning and can be used interchangeably in a given context.