jess 
(jĕs)
(jĕs)n.
A short strap fastened around the leg of a hawk or other bird used in falconry, to which a leash may be fastened.
tr.v. jessed, jess·ing, jess·es
To put jesses or a jess on (a hawk, for example).
[Middle English ges, from Old French, pl. of jet, something thrown, from Vulgar Latin *iectus, alteration of Latin iactus, past participle of iacere, to throw; see yē- in the Appendix of Indo-European roots.]