Varvel

An old-fashioned swivel, orig, OFr: vervelle = joint
Found on https://sites.google.com/site/breckfalconry/glossary

Varvel

• (n.) In falconry, one of the rings secured to the ends of the jesses.
Found on http://thinkexist.com/dictionary/meaning/varvel/

Varvel

Var'vel noun [ French vervelle .] In falconry, one of the rings secured to the ends of the jesses. [ Written also vervel .]
Found on http://www.encyclo.co.uk/webster/V/8

Varvel

A less used piece of equipment. This flat silver or brass ring served several purposes. It was attached at the end of a long slitless jess as the attachment for the leash, but also served as the quick release mechanism when hunting. (A single strip of leather or rope could be attached to the glove, passed through the rings, and held by the falconer...
Found on http://www.themodernapprentice.com/glossary.htm

varvel

metal ring attached to hawk's jess that connects to a leash
Found on http://phrontistery.info/v.html
No exact match found