A FEW POPULAR ANSWERS (there are several others):
BACKSTROKE, BIRTHPLACE, BREASTSTROKE, CORKSCREW, DOWNSTREAM, DUMBSTRUCK, EARTHSHAKING, ERSTWHILE, FILMSTRIP, HANDSPRING, JOCKSTRAP, LENGTHWISE, MATCHSTICK, NIGHTSHIRT, NIGHTSPOT, OFFSPRING, PITCHBLENDE, SONGSTRESS, SPENDTHRIFT, SPORTSWRITER, SWITCHBLADE, THUMBSCREW, WITCHCRAFT.