The Collaborative International Dictionary of English v.0.48:
Rescuer \Res"cu*er\ (-k?-?r), n. One who rescues. [1913 Webster]WordNet (r) 3.0 (2006):
rescuer n 1: a person who rescues you from harm or danger [syn: savior, saviour, rescuer, deliverer] 2: someone who saves something from danger or violence [syn: rescuer, recoverer, saver]