Longman Dictionary of Contemporary English
Wiktionary
a. 1 direct, forthright(,) and honest 2 (context sports English) one-on-one adv. directly, forthrightly(,) and honestly
WordNet
adj. forthright and honest; "had a man-to-man talk about the facts of life"
being a system of play in which an individual defensive player guards an individual offensive player; "one-on-one defense" [syn: one-on-one]
adv. directly; "we must talk man-to-man"
Usage examples of "man-to-man".
Young clerks like to use a zone coverage, whereas the oldtimers prefer a loose man-to-man, so you can wander and think, pick up an armload of items, frown, turn around, put them all back and start over again.
Perhaps making a true, man-to-man kill on an American plane would clean the slate, would erase the shame of what he'd done.
Besides, his man-to-man way of meting out punishment was preferable to the impersonal retribution of the Uniform Code of Military Justice.