1. a marriage or union between people of unequal social rank or status
Usage: formal; often implies disapproval from the perspective of the higher-ranking party
2. an unsuitable alliance or association of any kind
Usage: extended use beyond marriage

Examples

• The aristocratic family viewed their daughter's marriage to a merchant as a mesalliance.
• In the novel, the protagonist's mesalliance shocked high society.
• The business mesalliance between the two companies proved disastrous.
• Her parents considered the engagement a mesalliance beneath their family's standing.
• The mesalliance of traditional values with modern practices created tension in the community.
• Critics saw the merger as a mesalliance that would damage both brands.