also: おおが
noun
large saw; framed pit saw
Refers to a large saw, especially a traditional two-person pit saw used for ripping logs into boards.
昔の大工は大鋸で丸太を板に挽いた。
Carpenters in the old days ripped logs into boards with a large pit saw.
鋸 is the general word for a saw; 大鋸 specifically refers to a large saw, often a pit saw.
Compound of 大 (large) and 鋸 (saw). The reading おが is a contraction of おおが.