Source : Webster's Revised Unabridged Dictionary (1913)

Hetairism \He*tair"ism\, Hetarism \Het"a*rism\, n. [Gr. ? a
   companion, a concubine, fem. of ? a comrade.]
   A supposed primitive state of society, in which all the women
   of a tribe were held in common. --H. Spencer. --
   {Het`a*ris"tic}, a.