man power Share definition Flag Man power, or sometimes "manpower", refers to the power of one's manhood, i.e. his libido, virility and sexual prowess. 1) Rocco's man power is off the charts! Look at him hammer that ass! 2) Here's a viagra to boost your man power for tonight's gangbang man power by Ron McD January 11, 2008 Get the man power mug.