Definitive Jest

Entry: jaspers (n.)

In context: "'The Nelson Eddy guys in silly hats and equestrian jaspers.'"

Definition: 

I can't figure out what he's talking about here - I've been trying to find some sort of equipment or clothing-related usage of jaspers, but no luck.  Then again, I don't really know much about the equestrian world.  Actually, I don't even like horses.  I like pretty much all animals, but for whatever reasons, I don't get the appeal of horses. 

If you wanted my vote on horse for animal of the year it would be nay.

1. A kind of precious stone.
 a. As rendering of Greek ἴασπις or Latin iaspis, name among the ancients for any bright-coloured chalcedony except carnelian, the most esteemed being of a green colour.


but also, while not really relevant here, but interesting:

U.S. colloq.  A person, fellow: usu. with contemptuous overtones; spec. a rustic simpleton, ‘hick’. Also (with capital initial) used as a nickname (see quot. 1929, 1952).


Other:

SNOOT score: 1
 
Page: 1011

Source: Oxford English Dictionary