As nouns the difference between jessie and jess
is that jessie
is a cowardly person, especially a man; an effeminate man while jess
is (falconry) a short strap fastened around the leg of a bird used in falconry, to which a leash may be fastened or jess
can be a compact coal-like, velvet-black mineral, with a polish making it fit for use in jewelry.
As a proper noun jessie
is a pet form of jane and jessica, also used as a formal female given name.
As a verb jess is
(falconry) to fasten a strap around the leg of a hawk.