tetramerous

adjective

te·​tram·​er·​ous te-ˈtra-mə-rəs 

: having or characterized by the presence of four parts or of parts arranged in sets of four

tetramerous flowers

Word History

Etymology

New Latin tetramerus, from Greek tetramerēs, from tetra- + meros part — more at merit entry 1

First Known Use

1826, in the meaning defined above