Merriam-Webster Collegiate Dictionary - congener

 noun  Etymology: Latin, of the same kind, from com- + gener-, genus kind — more at kin  Date: circa 1736  1. a member of the same taxonomic genus as another plant or animal  2. a person, organism, or thing resembling another in nature or action the New England private schools and their ~s west of the Alleghenies — Oliver La Farge  3. a chemical substance related to another  • ~ic adjective  • ~ous adjective