di-, dicho-, dich-

(Greek: number two; twice, divided, double; unalike; a number used as a prefix)

diacanthous (adjective) (not comparable)
Regarding a plant or animal having two spines: Some beetles are known to be diacanthous, possessing two thorns or needle-like projections.
diacid (s) (noun), diacids (pl)
An acid that can combine with two acid radicals: A diacid has two acid hydrogen atoms in each molecule which can be exchanged with a metal or it can react with a basic substance.
diadelphous (adjective) (not comparable)
A description of stamens or flowers that have the stamen filaments grouped into two bundles or groups: Some members of the bean family are diadelphous, as the sweet pea.
dianthous
A condition of a flower that is pollinated from another flower of the same plant.
diarch
One of two rulers.
diarchy
diarchy, duarchy
A government by two rulers.
dibrachia
dicephalous
dicephaly
dicheilia
dicheria
dichogamous
dichogamy
dichogeny