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]

Moby Thesaurus II by Grady Ward, 1.0:

48 Moby Thesaurus words for "gens":
   animal kingdom, ashram, blood, body, breed, brood, caste, clan,
   class, colony, commonwealth, commune, community, deme,
   economic class, endogamous group, extended family, family, folk,
   house, kind, kinship group, line, lineage, matriclan, moiety,
   nation, nuclear family, order, patriclan, people, phratria,
   phratry, phyle, plant kingdom, race, sept, settlement,
   social class, society, species, stem, stirps, stock, strain,
   subcaste, totem, tribe



Bouvier's Law Dictionary, Revised 6th Ed (1856):

GENS. A word used by the Romans to represent race and nation. 1 Tho. Co.
Litt. 259, n. 13. In the French law, it is used to signify people or
nations, as Droit des Gens, the law of nations.