D defs.my
Entry 2 senses Webster, 1913

Holdfast

/hōl'-făstˌ/ · Hold·fast · IPA /hˈoʊlfˌæst/
01 n. Something used to secure and hold in place something else, as a long flat-headed nail, a catch a hook, a clinch, a clamp, etc.; hence, a support.
  1. 1.
    Something used to secure and hold in place something else, as a long flat-headed nail, a catch a hook, a clinch, a clamp, etc.; hence, a support.
  2. 2.
    A conical or branching body, by which a seaweed is attached to its support, and differing from a root in that it is not specially absorbent of moisture.(Bot.)