n.a large two-handed saw formerly used to cut logs into planks; one man stood above the log and the other in a pit below
英汉双解大词典
pitsaw/ˈpɪtˌsɔː/
1.
N（名词）
a large saw formerly used for cutting logs into planks, operated by two men, one standing on top of the log and the other in a pit underneath it 大锯