moss

Any of various small, green, seedless plants growing on the ground or on the surfaces of trees, stones, etc.; now specifically, a plant of the phylum Bryophyta (formerly division Musci).

A kind or species of such plants.

Any alga, lichen, bryophyte, or other plant of seemingly simple structure.

“Irish moss”

A bog; a fen.

“the mosses of the Scottish border”

To become covered with moss.

“An oak whose boughs were mossed with age.”

To cover (something) with moss.