IPA: /ˈwɒtʃkeɪs/
KK: /ˈwɑːtʃkeɪs/
The outer part of a watch that protects the inner workings and mechanism.
He carefully polished the watchcase to make it shine.
Watchcase → The word is formed from "watch" (from Old English *wæccan*, meaning to be awake or to guard) and "case" (from Latin *casa*, meaning house or shelter). A watchcase is essentially a protective house for a watch, designed to guard it.
Think of 'guarding' something ('watch') by putting it in a 'shelter' ('case') — that's why a watchcase is a protective covering for a watch.
No commonly confused words.