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]