男子汉 emphasizes masculine virtues like courage, responsibility, and toughness. The full form 男子汉大丈夫 (nánzǐhàn dàzhàngfu) is even more emphatic.
history
汉 originally referred to the Han dynasty and its people. Over time, 汉子 came to mean 'fellow' or 'man,' giving 男子汉 its connotation of a strong, upstanding man.
