رُومٌ
2.
الرُّومُ
A certain nation, (M, K,) well known; (M;) [said by the Arabs to be] descendants of Er-Room, the son of Esau (عيصُو [so called by the Arabs]), (T, * S, K,) the son of Isaac the Prophet; (TA;) [i. e. the Greeks; generally meaning, of the Lower Empire; but sometimes, only those of Asia; and sometimes those of the Lower Empire together with all the nations of Europe beside: the ancient Greeks are more properly called by the Arabs اليُونَانُ:] one says
رُومِىٌّ and رُومٌ; (S, K;) the former of these two appellations being applied to a single person, (M, K,) and the latter being the plural, (S, K,) [or rather a coll. gen. n.,] like زِنْجِىٌّ and زِنْجٌ; (AAF, S, M;) the former being distinguished from the latter only by the doubled ى, like as تَمْرَةٌ is distinguished from تَمْرٌ its plural [or coll. gen. n.] only by the ة: (S:) and رُومِىٌّ has for [its proper] plural
أَرْوَامٌ. (TA.) [It is also applied to The country of the nation, or people, so called, both in Europe and Asia, and sometimes only in Asia. Hence, بَحْرُ الرُّومِ
The Sea of the Greeks; meaning the Mediterranean Sea.]