περόνιον

τό
A. small peg or pin, Ph. Bel. 62.14, Hero Aut. 28.1, Spir. 1.42.
II. shackle or ring into which a bolt fits, Ph. Bel. 76.4.
Liddell, Scott & Jones
A Greek-English Lexicon, 1940
An open-access project