Definition of BIL in English:

BIL

noun

informal
  • A person's brother-in-law.

    ‘my Gran's sister married her BIL’
    • ‘Tragically, my sister passed away in 1997, and my BIL had the great good fortune of meeting, and falling in love with, a simply wonderful woman, whom he married in 2001.’
    • ‘Her BIL is a vegetarian.’
    • ‘We usually open family presents with my BIL, SIL and nephew on Christmas morning.’
    • ‘Dinner was a great success despite me nearly strangling my BIL for phoning up to tell me how to cook the sprouts properly!’
    • ‘On the way home my BiL phoned; my MiL is in hospital.’
    • ‘At the end of the day, the issue is your BIL, not your sister.’

Origin

1960s: abbreviation.