heterogamy

Concise Oxford English Dictionary © 2008 Oxford University Press:
heterogamy /ˌhɛtəˈrɒgəmi/

▶noun

• 1 chiefly Zoology alternation of generations, especially between sexual and parthenogenetic generations.

• 2 Botany a state in which the flowers of a plant are of two or more types.

• 3 marriage between people from different backgrounds.

– derivatives
heterogamous adjective.

– origin C19: from hetero- + Gk gamos ‘marriage’.