Pronunciation: (fif'tē-fif'tē), [key]
equally good and bad, likely and unlikely, favorable and unfavorable, etc.: a fifty-fifty chance of winning.
1. in an evenly or equally divided way: The board voted fifty-fifty on the merger.
2. go fifty-fifty (on), to share equally in the cost, responsibility, or profits (of): We went fifty-fifty on the dinner check. Also,50-50.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.