Intermarriage is marriage between people from different groups, such as different religions, ethnic backgrounds, or social classes. When a Jewish person marries a Christian person, or when someone from one country marries someone from another, that's intermarriage. The word specifically highlights the crossing of traditional boundaries that once might have kept these groups separate.

Throughout history, many societies discouraged or even forbade intermarriage between certain groups. Some cultures believed people should only marry within their own community to preserve traditions and identity. But attitudes have changed dramatically in many places. In America today, intermarriage between people of different races, religions, and backgrounds has become common and widely accepted, though some families and communities still prefer marriages within their own group.

The word can feel a bit clinical or old-fashioned because it emphasizes difference. Many people today simply say “marriage” rather than calling attention to the fact that partners come from different backgrounds. When historians discuss intermarriage, they're often exploring how societies have changed their views about who can marry whom, and how families blend different traditions and cultures together.