Mosstrooper is an old term that refers to raiders who operated in the Anglo-Scottish borders. Finding synonyms for this word can be challenging, as it is quite niche and obsolete. However, some possible alternatives include borderer, reiver, marauder, pillager, raider, bandit, brigand, outlaw, corsair, or pirate. These words evoke the idea of individuals or groups who engage in raiding, looting, and pillaging along borders or coastlines. While these terms may not be exact synonyms of Mosstrooper, they share some similarities in terms of the activities they do and the territories they operate in. Overall, these words conjure up images of daring and dangerous individuals who operate on the fringes of society and challenge the established order.