1) Scottish freebooter 
The term cateran (from the Gaelic ceathairne, a collective word meaning `peasantry`) historically referred to a band of fighting men of a Scotland Highland clan; hence the term applied to the Highland, and later to any, marauders or cattle-lifters. An individual member is a ceithernach or catanach. According to Randy Lee Eichoff it derives from .....
a Scottish military irregular or brigand
• (n.) A Highland robber: a kind of irregular soldier.
Cat'e·ran noun [ Gael. ceatharnach . Confer Kern Irish foot soldier.] A Highland robber: a kind of irregular soldier. [ Scot.] Sir W. Scott. 
A cateran was a Highland irregular soldier or raider.
a Highland robber.