A keyhole saw (also called a jab saw or drywall saw) is a long, narrow saw that is used for cutting small features in building materials such as drywall and plywood. Typically a keyhole saw has a sharpened point which can be pushed through soft materials such as drywall without pre-drilling a hole for the blade. The name derives from this method of insertion.
A power tool serving largely the same function, but which works more quickly and more accurately, is a spiral saw .