noun
A somewhat formal or literary term for a good-looking man. In casual speech, イケメン is far more common.
彼はまさに好男子という言葉がぴったりの人だ。
He is exactly the kind of person the word 'handsome man' fits perfectly.
美男子 also means 'handsome man' but is more common than 好男子. 好男子 has a slightly more refined or classical nuance.
Compound of 好 (good, favorable) and 男子 (man, male). The exact historical derivation is uncertain, but the word follows a standard Sino-Japanese pattern.