A resilient metal item, circular or nearly circular, which is designed to be inserted into an internal or external groove and retained by its own spring action, or it may have external prongs or projections designed to be inserted into a hole and retained by spring action of the prongs which grip by imbedding into the material. for items having internal prongs which perform the same function, see push on nut. it is used to keep and/or lock a part(s) in position, as a ball bearing on a shaft or in a housing. see also clip, retaining and pin, lock. excludes ring, connecting, round.