1. Restraint that attaches to something or holds something in place
   "The carpenter used a holdfast to secure the workpiece to the bench";
   - fastener, fastening, fixing
    
2. (biology) a root-like structure that anchors aquatic plants or algae to a surface
   "Kelp uses its holdfast to attach to rocks on the ocean floor"

1. Remain stuck to; keep in place
   "Will this wallpaper hold fast to the wall?";
   - adhere, bond, bind, stick, stick to

Derived forms: holdfasts, holding fast, holds fast, held fast

Type of: attach, constraint, restraint

Encyclopedia: Holdfast, Worcestershire