Kinktionary
More like guidelines and a lot less like definitions.
Fetish
A fetish refers to a specific object, behavior, body part, or fantasy that can sometimes be necessary for a person to achieve sexual enjoyment or arousal, but it's not always required to be physically present. While fetishes can involve specific objects, behaviors, or body parts, they can also involve imagining or fantasizing about certain things without requiring them to be physically present. A fetish can sometimes involve a psychological or emotional component, not just a physical one.
There is often overlap between kinks and fetishes and sometimes the two terms are used interchangeably to describe a unique 'turn on.'
On FetLife the Fetishes added to the fetish section on profiles tend to describe things that people consider to be sexy or that turn them on, although sometimes people also create fetishes as in-jokes between friends for other things they really like (e.g: a nice cup of tea and a slice of cake). More information about the fetishes section on FetLife can be found here.