reliever
nounOne that provides relief.
nounA relief pitcher.
nounOne who or that which relieves or gives relief.
nounIn gunnery, an iron ring fixed to a handle by means of a socket, which serves to disengage the searcher of a gun when one of its points is retained in a hole.
nounA garment kept for being lent out.
nounIn mech.: A release; a device for releasing some part of a mechanism at a certain time or position.
nounA device, such as a spring or elastic substance, for preventing shocks on a machine or part.
nounOne who, or that which, relieves.
nounA
Someone who fills in for another.