c. 1200, "human; characteristic of human beings," from man (n.) + -ly (1). Sense of "possessing virtues proper to a male person" (resoluteness, steadfastness, reliability) is from early 13c. Meaning "masculine" is attested from late 14c. Old English had werlic "male, masculine, manly."[manly etymology, manly origin, 英语词源]