noun
man of principle; man of firm character; man of steadfast beliefs
A somewhat literary or formal term for a man who is unwavering in his principles and moral backbone. Not an everyday word; often used in descriptions of admirable, resolute men.
彼はどんな誘惑にも負けない硬骨漢だ。
He is a man of principle who won't give in to any temptation.
祖父はまさに硬骨漢
My grandfather was truly a man of steadfast beliefs; he never compromised his convictions throughout his life.