'Lowland' definitions:

Definition of 'lowland'

(from WordNet)
adjective
Of relatively low or level country [ant: highland(a), upland]
noun
Low level country [ant: highland, upland]

Definition of 'Lowland'

From: GCIDE
  • Lowland \Low"land\, n. Land which is low with respect to the neighboring country; a low or level country; -- opposed to highland. [1913 Webster]
  • The Lowlands, Belgium and Holland; the Netherlands; also, the southern part of Scotland. [1913 Webster]