The Collaborative International Dictionary of English v.0.48:

Gens \Gens\ (j[e^]nz), n.; pl. Gentes (j[e^]n"t[=e]z). [L. See
   Gentle, a.] (Rom. Hist.)
   1. A clan or family connection, embracing several families of
      the same stock, who had a common name and certain common
      religious rites; a subdivision of the Roman curia or
      tribe.
      [1913 Webster]

   2. (Ethnol.) A minor subdivision of a tribe, among American
      aborigines. It includes those who have a common descent,
      and bear the same totem.
      [1913 Webster]

WordNet (r) 3.0 (2006):

gens
    n 1: family based on male descent; "he had no sons and there was
         no one to carry on his name" [syn: name, gens]