adjective. Consisting of two parts or segments, as the tarsus in certain insects.

adjective. Having flower parts, such as petals, sepals, and stamens, in sets of two.

Consisting of or divided into two parts; bipartite.

Specifically In botany, having two members in each whorl: said of flowers. Sometimes written by botanists 2-merous.

In entomology, having two-jointed tarsi; specifically, pertaining to the Dimera.

adjective. Composed of, or having, two parts of each kind.

adjective. in two parts: in a flower each whorl (of flower parts) has two flower parts.

"Again, it may be remarked that many of these orders show a tendency towards a regular diminution of the assumed normal number of their parts; thus, among _Onagraceæ_, _Circeia_ and _Lopezia_ may be referred to, the former normally dimerous, the latter having only one perfect petal."

dimerous thorax  pentamerous  tetramerous  trimerous  

dimer  dimery