[ter.rain] n [F, land, ground, fr. (assumed) VL terranum, alter. of L terrenum, fr. neut. of terrenus of earth--more at terrene] (1766) 1 a (1): a geographical area (2): a piece of land: ground b: the physical features of a tract of land
2: terrane 1 3 a: a field of knowledge or interest: territory b: environment, milieu