Definition of big deal in English:

big deal

noun

US
  • 1An important business transaction or contract.

  • 2Something considered important; a cause for excitement or concern.

  • 3Used as an ironical exclamation to express one's contempt for something regarded as impressive or important by another person.

Origin

Early 20th century; earliest use found in Frank Norris (1870–1902), novelist. From big + deal.

Pronunciation

big deal

/ˌbɪɡ ˈdiːl/