Etymology

Derived from the preposition op ‎(“on, upon”), which also has an adverbial sense “open”, as has German auf. The infix -en- may stem from the older affen ‎(“open”), from Old High German offan, which itself is cognate with German offen, Dutch open, and English open. (The phonetic similarity between Luxembourgish oppen and Dutch/English open is thus accidental.) Other dialects of Moselle Franconian and Ripuarian generally use the stem opp- (without -en-) for the adjective “open”.

Pronunciation

• IPA^(key): /ˈopən/