From Old English sagu, from PIE *sek- 'to cut' — the same root behind section, insect, and dissect.
A hand tool or power tool with a toothed blade used for cutting hard materials such as wood or metal.
From Old English sagu 'saw,' from Proto-Germanic *sagō, from PIE root *sek- 'to cut.' The same root gave Latin secāre 'to cut,' making saw a distant cousin of section, insect, and dissect. Key roots: *sek- (Proto-Indo-European: "to cut").