Source : Webster's Revised Unabridged Dictionary (1913)

Gravamen \Gra*va"men\, n.; pl. L. {Gravamina , E. {Gravamens}.
   [L., fr. gravare to load, burden, fr. gravis heavy, weighty.
   See {Grave}, a.] (Law)
   The grievance complained of; the substantial cause of the
   action; also, in general, the ground or essence of a
   complaint. Bouvier.