What is a lawnmower?

It is apparent, no?

A lawn mower mows the lawn.

Don't cut your hair with it, please, unless you want to die.

Answer. Basically a lawnmower is someone or something that cuts grass. The first lawnmower was a man with a scythe. The first machine was a cylinder of blades rotating against a sole plate and driven by the road wheels. The latest types are Rotary mowers where a single blade turns at speed and cuts the grass.