Other forms: lockets
A locket is a tiny hinged case worn on a chain, with a picture or a lock of hair hidden inside. A silver locket, open the locket, wear a locket.
It is a keepsake rather than a decoration: the point is what is inside it and who else knows. Victorian mourning lockets held hair from somebody who had died, which was a widespread custom and is now a museum category. Note that the -et ending is a diminutive, so a locket is a little lock — meaning a fastening rather than hair, though the coincidence has suited the object for two centuries.
1nounlocketA tiny hinged case on a chain with a picture inside.
“The locket held a photograph about the size of a stamp.”
locket is a piece of jewellery.
Old French loquet is a diminutive of loc, a lock or latch — a locket was originally a small fastening. The jewellery sense came from the catch that holds the case shut.
Old English
loc
Anglo-Norman
loc
French
loquet
English, today
locket
From French loquet, from a diminutive of Anglo-Norman loc, itself from Old English loc, whence lock.
Etymology from Wiktionary, CC BY-SA