Green’s Dictionary of Slang

(US) an effeminate young man.

1896		Ade Artie (1963) 4: W’y, out there last night I see the measliest lot o’ jays — regular Charley-boys — floatin’ around with queens. [Ibid.] 88: There was too many Charley-boys ridin’. You know the kind I mean — them dubs with the long hair and the badges all over the coats.
1902		Ade Forty Modern Fables 19–20: From the Minute that any Charley-Boy shows up at my Work-Shop, I talk about Him and nothing else.
1913		J. London Valley of the Moon (1914) 91: It’s all right for Charley-boys, but a man that is a man don’t like bein’ chased by women.
1923		Ade College Widow 14: A lady can’t walk across the campus without a lot of you Charley boys trying to get new with her.