A saw is a tool that uses a hard blade or wire with an abrasive edge to cut through softer materials. The cutting edge of a saw is either a serrated blade or an abrasive. This tool may be worked by hand, or powered by steam, water, or electric power.

Abrasive Saw Blade

A saw is a tool that uses a hard blade or wire with an abrasive edge to cut through softer materials.…

"A reaping hook; a curved blade of steel (anciently also of bronze) having the edge on the inner side of the curve, with a short handle or haft, for cutting with the right hand grain or grass which is grasped by the left." —Whitney, 1889
<p>This sickle has a serrated edge on the inside curve of the blade.

Sickle with Serrated Edge

"A reaping hook; a curved blade of steel (anciently also of bronze) having the edge on the inner side…