Heterophile is an alternate term to heterosexual and once competed with it for currency, but only did so successfully in Scandinavia. It is a parallel concept to homophile

In Scandinavia and Finland, the word heterofil is a gender-neutral term, like "heterosexual" in Canada and the United States.

Medical

Heterophile Antibodies are antibodies induced by external antigens (Heterophile Antigens) that nevertheless cross-react with self-antigens. For example antibodies against Group A Streptococcus cell walls can also react with human heart tissues. These are considered heterophile antibodies.