Middle English pliaunt, borrowed from Anglo-French pliant, plyaunt "able to be bent or folded, obedient, compliant," from present participle of plier "to fold, bend"
plasticpliablepliantductilemalleableadaptable mean susceptible of being modified in form or nature. plastic applies to substances soft enough to be molded yet capable of hardening into the desired fixed form. pliable suggests something easily bent, folded, twisted, or manipulated.