an obssession; a certain liking towards.
she has a fettish for men with fauxhawks.
spelled with two t's unlike its dirtier counterpart, this word simply means to have a weird or uncommon obsession with something. It can be something you do, or something you like, but it has NO sexual connotation. It just means that you like whatever it is A LOT.
One can have any number of fettishes, such as:
a cheese fettish, a pink fettish, or even a Facebook fettish.