Meaning : Directly between two individuals.
Example :
One-on-one instruction.
Meaning : Being a system of play in which an individual defensive player guards an individual offensive player.
Example :
One-on-one defense.
Synonyms : man-to-man
Meaning : (of two persons) in direct encounter.
Example :
Preferred to settle the matter one-on-one.
Interviewed her person-to-person.
Synonyms : person-to-person