one-on-one

one-on-one (comparative more one-on-one, superlative most one-on-one)

1. (chiefly Canada, US) Involving direct communication or competition between two people.
   • 1999, United States. Congress. Senate. Committee on the Judiciary. Subcommittee on Criminal Justice Oversight, The Clinton Justice Department's Refusal to Enforce the Law on Voluntary Confessions: Hearing, page 56:

     Such one-on-one “swearing contests” are routinely decided in favor of law enforcement officers, but in this case the district court sided with the accused bank robber.

2. (sports) Involving one attacker and one defender.
   • 2011 September 24, David Ornstein, “Arsenal 3 - 0 Bolton”, in BBC Sport‎:

     After several near misses, Van Persie finally reached three figures by turning in Walcott's cross before Jaaskelainen saved from Walcott when one-on-one.

   • 2024 January 13, Callum Matthews, “Newcastle United 2-3 Manchester City”, in BBC Sport‎:

     Swedish striker Isak was also foiled by Ortega in a one-on-one opportunity shortly before half-time. If converted, that may have put the game beyond City's reach.

3. (mathematics) bijective or injective

• one-to-one (British)

one-on-one (plural one-on-ones)

1. A contest involving only one player on each side, especially of an activity often involving teams.

   Why don't we play a little one-on-one until the others show up.

   He was willing to go one-on-one with the District Attorney himself.

• (contest between two people): triple O

• face-to-face
• man-to-man