Refers to a physical lock, typically a padlock or a door lock. The word is neutral and common.
自転車に錠前をかける。
I put a lock on my bicycle.
この錠前は壊れている。
This lock is broken.
locksmith; lock shop
lock breaking; lock picking
Compound of 錠 (じょう, 'lock') and 前 (まえ, here a suffix meaning 'device' or 'fitting'). The exact derivation of 前 as a suffix is uncertain, but it appears in other tool names.