say it: WUHN-uh-nahn
one-on-one is an adjective and adverb meaning "directly between two individuals". It carries 3 recorded senses.
being a system of play in which an individual defensive player guards an individual offensive player
“one-on-one defense”
sport
(of two persons) in direct encounter
“preferred to settle the matter one-on-one”
“interviewed her person-to-person”
Definitions, synonyms and semantic relations for one-on-one come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.