Mundane means ordinary and dull in an everyday way. Mundane tasks, the mundane details, thoroughly mundane.
It is mildly dismissive: mundane work is necessary and uninteresting, which is most of everybody's week. The older sense is worldly as against spiritual — mundane concerns, the mundane world — and that is where the word comes from, since mundus means the world. So the mundane is literally the earthly, and its dullness is an English addition.
1adjectivemundaneOrdinary and dull in an everyday way.
“Most of the job is mundane: answering emails, filing reports and sitting in meetings.”
mundane is a quality of ordinariness.
Also accepted in games: boring
Latin mundanus comes from mundus, the world. The sense of dullness is English: what belonged to this world came to mean what was merely ordinary.
Latin
mundānus
Old French
mondain
Middle English
mondeyne
English, today
mundane
From Middle English mondeyne, from Old French mondain, from Latin mundānus, from Latin mundus (“world”). Compare Danish mondæn. ordinary Compare typologically несусве́тный (<~ не- + сусве́тный < свет).
Etymology from Wiktionary, CC BY-SA