Definition of fornicate in US English:



[no object]humorous, formal
  • (of two people not married to each other) have sexual intercourse.

    • ‘They traveled and probably fornicated in cars made by giant multinational corporations.’
    • ‘He thus has the knowledge that he should avoid fornication, but he fornicates nonetheless because he actually sees the fornication as an act of pleasure to be pursued.’
    • ‘A man of irreproachable personal piety who nevertheless has no objection to his neighbors’ boozing on the Sabbath or fornicating in haylofts is not a Puritan.’
    • ‘If our patients had no alternative but to fornicate, perhaps it would be a case of passing the buck.’
    • ‘The final chorus in this production reverses the emotional polarities of the whole opera: singing about their new-won freedom, the humans fight, flirt and fornicate.’


Middle English (as fornication): from ecclesiastical Latin fornicat- ‘arched’, from fornicari, from Latin fornix, fornic- ‘vaulted chamber’, later ‘brothel’.