An example of superfluous is a buying a stuffed animal for a child who already has too many stuffed animals.
A superfluous remark.
With a full rain suit, carrying an umbrella may be superfluous.
Origin of superfluous
- Middle English from Old French superflueux from Latin superfluus from superfluere to overflow super- super- fluere to flow bhleu- in Indo-European roots
From American Heritage Dictionary of the English Language, 5th Edition