What is the meaning of 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.

A bog; a fen.

To become covered with moss.

To cover (something) with moss.

To relax, chill out.

second-person singular subjunctive present indefinite of mos

Source: wiktionary.org