1
chiefly Scotland : bog, swamp
especially : a peat bog
2
a
: any of a division (Bryophyta) of plants characterized by a gametophyte having a small leafy often tufted stem bearing sex organs at its tip
also : a clump or sward of these plants
b
: any of various plants resembling moss in appearance or habit of growth
3
: a mossy covering

moss

2 of 2

verb

mossed; mossing; mosses

transitive verb

: to cover or overgrow with moss

Examples of moss in a Sentence

Noun Moss covered the fallen logs.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Noun
Ferns and mosses cover the towering canyon walls, surrounding the trail with dense vegetation. — Cu Fleshman, Travel + Leisure, 12 Nov. 2026 Mushrooms and other fungi, lichens, insects and other arthropods, slime molds, salamanders, springtails, birds, and mosses are some of the organisms that can be found inside, on, or under these logs. — Pamm Cooper, Hartford Courant, 8 Nov. 2026 The Magic 9, the successor to the Magic 8 Pro, looks like a triple-eyed, moss-green robo-creature designed to blend in with an overgrown, post-apocalyptic wasteland. — Kimberly Gedeon, PC Magazine, 5 Nov. 2026 Away from the shore, the tundra is barren, a broad expanse of moss, lichen, and exposed rock. — Joshua Yaffa, New Yorker, 2 Nov. 2026 See All Example Sentences for moss

Word History

Etymology

Noun

Middle English, from Old English mos; akin to Old High German mos moss, Latin muscus

First Known Use

Noun

before the 12th century, in the meaning defined at sense 1

Verb

15th century, in the meaning defined above

Time Traveler
The first known use of moss was before the 12th century

Cite this Entry

“Moss.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/moss. Accessed 13 Nov. 2026.

Kids Definition

moss

noun
ˈmȯs
1
: any of a class of plants that have no flowers and produce small leafy stems forming sex organs at their tips and that grow in patches like cushions on rocks, bark, or damp ground
2
: any of various plants (as lichens) resembling mosses compare reindeer moss
mosslike
-ˌlīk
adjective
mossy
ˈmȯ-sē
adjective

Medical Definition

1
: any of a division (Bryophyta) of plants having a small leafy often tufted stem bearing sex organs at its tip see sphagnum
2
: any of various plants resembling mosses in appearance or habit of growth see club moss, iceland moss, irish moss

More from Merriam-Webster on moss

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!