IPA: /ˈlɒk.smɪ.θɪŋ/
KK: /ˈlɑkˌsmɪθɪŋ/
The skill and practice of creating, repairing, and opening locks.
He learned locksmithing to start his own business.
Locksmithing → It is formed from "lock" (from Old English *locc*, meaning to fasten or secure) and "smithing" (from Old English *smið*, meaning to work with metal). The word describes the craft of working with locks and metal to create or repair locking mechanisms.
Think of someone who 'works with metal' ('smithing') to 'fasten' or 'secure' things ('lock'). This helps you remember that locksmithing is the craft of making and repairing locks.