A gimp is any of the following:
- A cripple
- A particular kind of BDSM role
- Twisted silk, worsted, or cotton with cord or wire running through it, used chiefly as upholstery trimming.
- (in lacemaking) coarser thread which forms the outline of the design in some techniques.
- fishing line made of silk bound with wire.
The last three I got from the internet.
It's kinda a slur in the US in the sense that people claim it's a slur, but I've never heard anyone actually use it that way.