What does fedish mean?

Strictly speaking, with respect to sex, a fetish is "an object or bodily part whose real or fantasied presence is psychologically necessary for sexual gratification and that is an object of fixation to the extent that it may interfere with complete sexual expression." (Merriam Webster)

However ...

As used on this site, it does not necessarily refer to something that is "psychologically necessary," but only to something that has a significant positive impact on sexual gratification.