NOUN (1)

1. a member of a people who inhabited ancient Sumer;


ADJECTIVE (1)

1. of or relating to ancient Sumer or its inhabitants;

The Collaborative International Dictionary of English v.0.48:

Sumerian \Su*me"ri*an\, a. [Written also Sumirian.]
   Of or pertaining to the region of lower Babylonia, which was
   anciently called Sumer, or its inhabitants or their language.
   [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

Sumerian \Su*me"ri*an\, n. [Written also Sumirian.]
   A native of lower Babylonia, anciently called Sumer.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

Sumerian
    adj 1: of or relating to ancient Sumer or its inhabitants
    n 1: a member of a people who inhabited ancient Sumer