moss

Etymology

From Middle English mos, from Old English mos (“bog, marsh, moss”), from Proto-West Germanic *mos (“marsh, moss”), from Proto-Germanic *musą (“marsh, moss”), from Proto-Indo-European *mews- (“moss”). Cognate with Saterland Frisian Moas (“moss”), West Frisian moas (“moss”), Dutch mos (“moss”), German Low German Moss (“moss”), German Moos (“moss”), Danish mos (“moss”), Swedish mossa (“moss”), Icelandic mosi (“moss”), Latin muscus (“moss”), Russian мох (mox, “moss”), Polish mech. Doublet of mousse.

noun

1. 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).
2. (countable) A kind or species of such plants.
3. (informal) Any alga, lichen, bryophyte, or other plant of seemingly simple structure.
   Spanish moss
   Irish moss
   club moss
4. (now chiefly UK regional) A bog; a fen.
   the mosses of the Scottish border

verb

1. (intransitive) To become covered with moss.
   An oak whose boughs were mossed with age.
2. (transitive) To cover (something) with moss.