Cleat

I put a cleat in his mouth.

I put a cleat to him.

[...] the people of that island erected lofty spars along the seacoast, to which the look-outs ascended by means of nailed cleats, something as fowls go upstairs in a hen-house.

I had learned that cattle willingly walk down a ramp that has cleats to provide secure, nonslip footing.

Near-synonym: calk

He needs to put on five pieces of gear: his helmet, left glove, right glove, left cleat, and right cleat.