-ərəs adjective
Etymology: New Latin tetramerus, from Greek tetramerēs, from tetra- + -merēs (from meros part) — more at merit
: having or characterized by the presence of four parts:
a. of a flower : having the parts arranged in sets of four or multiples of four — often written 4-merous
b. : having four or apparently only four joints in each of the tarsi
tetramerous beetles