“大镰刀”的英语可以翻译为：scythe ...

他正在用一把大镰刀割草.He's cutting grass with a scythe.他正忙着干活, 在磨一把长柄大镰刀的刃儿.He was very busy, putting an edge on a scythe.长柄大镰刀嗖嗖地来回挥动.Scythes swished to and fro....