noun
grown man; full-grown man; adult male
Emphasizes physical maturity and strength; often used in contexts where a man is expected to be capable or brave, or when contrasting with a child or woman.
大の男が泣くとは情けない。
It's pathetic for a grown man to cry.
大の男が三人がかりでやっと運べる重さだ。
It's so heavy that it takes three full-grown men to carry it.