keychain (English) comes from English chain, from Middle English cheyne, from Old French chaine, from Latin catēna, from Proto-Indo-European kat- — cub; to weave, to braid; to link or weave...
keychain (English): A chain or ring to which a key may be attached;...
Definitions
A chain or ring to which a key may be attached;...
Ancestry of “keychain”, step by step
keychain traces back through two separate lines of ancestry.