from
The Collaborative International Dictionary of English v.0.48
Heterology \Het`er*ol"o*gy\, n. [Hetero- + -logy.]
1. (Biol.) The absence of correspondence, or relation, in
type of structure; lack of analogy between parts, owing to
their being composed of different elements, or of like
elements in different proportions; variation in structure
from the normal form; -- opposed to homology.
[1913 Webster]
2. (Chem.) The connection or relation of bodies which have
partial identity of composition, but different
characteristics and properties; the relation existing
between derivatives of the same substance, or of the
analogous members of different series; as, ethane, ethyl
alcohol, acetic aldehyde, and acetic acid are in
heterology with each other, though each in at the same
time a member of a distinct homologous series. Cf.
{Homology}.
[1913 Webster]