noun.
In biology, the state or condition of being different in ancestry, but alike in appearance. See isomorphic, 2 .
noun.
In group-theory, the state or character of being isomorphic.
noun.
A similarity of crystalline form: as, between substances of analogous composition or atomic proportions, as the members of a group of compounds like the sulphates of barium, strontium, and lead
noun.
between compounds of unlike composition or atomic proportions.