What is "caterans"

Usage examples of "caterans".

M'Whirtle, instead of setting your men to break down the door, as if they were Highland caterans on a foray?

Yama thought that they must be soldiers, caterans or some other kind of irregulars, for they all wore bits of armor, mostly metal or resin chestplates painted with various devices, and wrist guards and greaves.

And when I remembered James More, and the red head of Neil the son of Duncan, I thought there was perhaps a fourth in the confederacy, and what remained of Rob Roy's old desperate sept of caterans would be banded against me with the others.