Wordnet 3.0
ADJECTIVE (2)
1. 
 forthright and honest; 
- Example: "had a man-to-man talk about the facts of life"2. 
 being a system of play in which an individual defensive player guards an individual offensive player; 
- Example: "one-on-one defense"[syn: one-on-one, man-to-man]
ADVERB (1)
1.  directly; 
- Example: "we must talk man-to-man"
WordNet (r) 3.0 (2006):
man-to-man
    adv 1: directly; "we must talk man-to-man"
    adj 1: forthright and honest; "had a man-to-man talk about the
           facts of life"
    2: being a system of play in which an individual defensive
       player guards an individual offensive player; "one-on-one
       defense" [syn: one-on-one, man-to-man]