How to say "doubles" in Japanese

• ダブルス
  nounCovers doubles as a pair-based format in sports such as tennis and badminton. This loanword is the usual way to refer to the doubles event or team in conversation and writing about those games.
  僕ぼくはダブルスのトーナメントでブレンドンと組くんだ。↗

  I teamed up with Brendon for the doubles tournament.
• 複ふくCommon
  nounAlso glossed as doubles in sports like tennis and badminton, but it is an abbreviation rather than an everyday word; as a common standalone way to say 'doubles' it is seldom the word you want.

For the sports sense of 'doubles' (tennis, badminton, etc.), 「ダブルス」 is the normal loanword; 複 is an abbreviation that appears mostly in set sports contexts and is otherwise rarely what you want.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• ダブルスdoubles (tennis, badminton, etc.)
• 複ふくdoubles (tennis, badminton, etc.)
• ダブルdoubles (e.g. in tennis)