A one-on-one situation, meeting, or contest involves only two people.
...a one-on-one therapy session.
= one-to-one
ADJ : usu ADJ n
•
One-on-one is also an adverb.
Talking one-on-one with people is not his idea of fun.
ADV : ADV after v
•
One-on-one is also a noun.
Holloway was beaten in a one-on-one with Miklosko just before half-time.
N-SING : oft N with n