Branches caught at Harry’s hair and robes, but he lay quiescent, his mouth lolling open, his eyes shut, and in the darkness, while the Death Eaters coed all around them, and while Hagrid sobbed blindly, nobody looked to see whether a pulse beat in the exposed neck of Harry Potter….
There are no more uses of "quiescent" in the book.
Show samples from other sources
She is always on the move and busy, but her boyfriend is quiet and quiescent.
Lady Bertram was perfectly quiescent and contented, and had no objections to make.