1a small ornamental case, typically made of gold or silver, worn round a person’s neck on a chain and used to hold things of sentimental value, such as a photograph.
2a metal plate or band on a scabbard.
Origin:
late Middle English(in sense 2): from Old French locquet, diminutive of loc 'latch, lock', of Germanic origin; related to lock1. sense 1 dates from the late 17th century
