The Collaborative International Dictionary of English v.0.48:
Lowlander \Low"land*er\, n. A native or inhabitant of the Lowlands, especially of the Lowlands of Scotland, as distinguished from Highlander. [1913 Webster]WordNet (r) 3.0 (2006):
Lowlander n 1: a native of the Lowlands of Scotland [syn: Lowlander, Scottish Lowlander, Lowland Scot]