bolt (v.)youdaoicibaDictYouDict
from bolt (n.) in its various senses; from a crossbow arrow's quick flight comes the meaning "to spring, to make a quick start" (early 13c.). Via the notion of runaway horses, this came to mean "to leave suddenly" (early 19c.). Meaning "to gulp down food" is from 1794. The meaning "to secure by means of a bolt" is from 1580s. Related: Bolted; bolting.
cleat (n.)youdaoicibaDictYouDict
c. 1300, clete "wedge," from Old English *cleat "a lump," from West Germanic *klaut "firm lump" (cognates: Middle Low German klot, klute, Middle Dutch cloot, Dutch kloot, Old High German kloz, German kloß "clod, dumpling"). In Middle English, a wedge of wood bolted to a spar, etc., to keep it from slipping (late 14c.). Meaning "thin metal plate for shoes, etc." is c. 1825.
pen (n.2)youdaoicibaDictYouDict
"enclosure for animals," Old English penn, penne, "enclosure, pen, fold," of uncertain origin, perhaps related to Old English pinn "pin, peg" (see pin (n.)) on notion of a bolted gate or else "structure made of pointed stakes."