holdfasts

Holdfasts are devices or structures that grip or secure.

In woodworking, a holdfast is a metal tool that clamps workpieces to a bench.

In biology, holdfasts are root-like structures that anchor seaweed and other organisms to rocks or surfaces—they grip rather than absorb nutrients like true roots.

The word also applies to any clamp, hook, or fastening device: The kelp's holdfast kept it anchored through the storm.