Definition of en passant in US English:

en passant

adverb

  • 1By the way; incidentally.

    ‘the group's disbandment was announced, almost en passant, by the president’
    • ‘Almost en passant, the album redefined the job and the self-image of the DJ.’
    in passing, incidentally, by the way, parenthetically, while on the subject, apropos
    View synonyms
    1. 1.1Chess By the en passant rule.
      • ‘If White plays another move he cannot then decide to capture en passant!’
      • ‘Only pawns can be captured en passant.’

Phrases

  • en passant rule (or law)

    • The rule that a pawn making a first move of two squares instead of one may nevertheless be immediately captured by an opposing pawn on the fifth rank.

      • ‘This en passant rule must happen on the current move of the game.’
      • ‘Although you may play a hundred games, and never have to use the En Passant rule, you should know it if your opponent uses it.’

Origin

Early 17th century: French, literally ‘in passing’.

Pronunciation

en passant

/ɑ̃pæˈsɑ̃//äNpaˈsäN/