clamp (n.)

device for fastening or holding, c. 1300, probably from Middle Dutch clampe (Dutch klamp), from Proto-Germanic *klam-b- "clamp, cleat;" cognate with Middle Low German klampe "clasp, hook," Old High German klampfer "clip, clamp;" also probably related to Middle Dutch klamme "a clamp, hook, grapple," Danish klamme "a clamp, cramp," Old English clamm "a tie, fetter," perhaps from the same root as Latin glomus "ball-shaped mass" (see glebe).

It took the place of earlier clam "clamp, brace," from Old English clamm "bond, fetter, grip, grasp" (see clam (n.)).

"to fasten with a clamp," 1670s, from clamp (n.). Related: Clamped; clamping.