A trimmer is a person who goes to a certain area of the Yorkshire Moors in England, where the craggy rock floor is coated in a thick and velvety moss covering.
The rocks are weathered and worn with age, and have formed deep crevices that are used as a
substitute for the
female genitalia. Lone walkers can be found face down in the rocks, appearing to sniff the moss, with their gentlemen inserted deep into a soft mossy crevice.
This act of
copulation helps to trim the moss and keep it under control. Hence the phrase - “Trimmers”.