holdfast(redirected from Hold-fast)
Also found in: Dictionary, Thesaurus, Encyclopedia.
1. Any of various devices used to fasten something securely.
2. Biology An organ or structure of attachment, especially the basal, rootlike formation by which certain seaweeds or other algae are attached to a substrate.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
holdfastthe basal part of the stripe (stalk) of large seaweeds such as Fucus , Laminaria, attaching the plant to the substrate.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005