- an abolitionist guerrilla of Missouri and Kansas in Civil War days
- a robber, raider, or plunderer
- [J-]Informal a person born or living in Kansasalso Jay′hawk·
Origin of jayhawkerfrom uncertain or unknown; perhaps
- One of the free-soil guerrillas in Kansas and Missouri during the border disputes of 1854 to 1859.
- A Unionist guerrilla.
- Jayhawker Informal A native or resident of Kansas.
Origin of jayhawkerFrom jayhawk a fictitious bird