- the caliber of having comparable intimate zooids or gonophores and dissimilar hydrants; said of certain hydroids.
- The quality of having similar intimate zooids or gonophores and dissimilar hydrants; -- stated of certain hydroids.
- In biology, production of similar or identical sexual organisms or reproductive parts from diverse stocks.
- Similarity in crystalline kind; specifically, that existing involving the crystals of chemical compounds that are not closely related in structure. See isomorphism.