How can superFluous?

bledda blobba do blah

The brides maid's dress she wore was so superfluous that it almost topped the brides wedding dress.

It would be 'superfluous' for Jane to buy another pair of shoes since she has a closet full of them. 'Superfluous' means exceeding what is needed or being wasteful.

The superfluous work had to be done even though we had already finished the project.

it means to go above and beyond what is required, like if your little brother asks you to get them a cup, and you get him a cup AND pour the water in it.