jig saw

(noun) a portable power saw with a reciprocating blade; can be used with a variety of blades depending on the application and kind of cut; generally have a plate that rides on the surface that is being cut. Synonyms: saber saw, jigsaw, reciprocating saw.

(noun) fine-toothed power saw with a narrow blade; used to cut curved outlines. Synonyms: jigsaw, scroll saw, fretsaw.