Jayhawker n. : A name given to a free-booting, unenlisted, armed man or guerrilla.

Example:
Any Jayhawker fans out there think they can hang with Missouri?

Taxonomy
Jayhawkers, Jayhawker, Kansas, Jayhawk, free encyclopedia, the Civil War, Origin, Kansans, Missouri, sanction, slaves, Missouri militia, The origin, prominence, pro-slavery, partisans, militia units, admission.

Defination from the web:
... Colonel James Montgomery in the movie Glory was referred to as "a real Jayhawker from Kansas. ...