Use pliancy to talk about either kind of adaptability — mental or physical. If you're able to adapt to different groups of people easily, adjusting your conversation to fit each situation, that's one kind of pliancy. If you've ever bent a rubbery doll into various complicated poses, that's another type of pliancy. The root of the word is the Old French ploiant, which means "bending and supple," but also "compliant and fickle." In the thirteenth century pliant even meant "turncoat" or "traitor."