Search Result for "heterology": 
Wordnet 3.0

NOUN (1)

1. (biology) the lack of correspondence of apparently similar body parts;

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]
WordNet (r) 3.0 (2006):

heterology n 1: (biology) the lack of correspondence of apparently similar body parts