- Immunology a genetic variant, esp. an antibody that acts as an antigen when introduced into the bodies of most other individuals of the same species
- Taxonomy an animal or plant specimen that shows physical characteristics, usually sexual ones, not shown in the holotype
- Taxonomy A biological specimen that is the opposite sex of a holotype.
- Immunology Any of several variants in the constant region of a given class or subclass of immunoglobulins that are caused by allelic variation and differ from individual to individual.
allo- + -type