(in mosses, ferns, etc.) one of the rootlike filaments by which the plant is attached to the substratum.

Origin of rhizoid

1855–60; rhiz- + -oid
Related formsrhi·zoi·dal, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for rhizoid

Historical Examples of rhizoid

British Dictionary definitions for rhizoid



any of various slender hairlike structures that function as roots in the gametophyte generation of mosses, ferns, and related plants
Derived Formsrhizoidal, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for rhizoid

"root-like," 1858, from Greek rhiza "root," literal and figurative (see rhizome) + -oid. As a noun from 1875.

Online Etymology Dictionary, © 2010 Douglas Harper

rhizoid in Medicine




Having irregular branching. Used of a form of bacterial growth.


A slender rootlike filament by which mosses, liverworts, and fern gametophytes attach to the substratum and absorb nourishment.
A rootlike extension of the thallus of a fungus.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

rhizoid in Science



A slender, rootlike filament by which mosses, liverworts, and the gametophytes of ferns attach themselves to the material in which they grow.
A branching, rootlike extension by which algae and fungi absorb water and nutrients.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.