Manly, a. [Compar. Manlier; superl. Manliest.]
Etymology: [Man + -ly. Cf. Manlike.]
Having qualities becoming to a man; not childish or womanish; manlike, esp. brave, courageous, resolute, noble. Let's briefly put on manly readiness. Shak. Serene and manly, hardened to sustain The load of life. Dryden.
Syn. -- Bold; daring; brave; courageous; firm; undaunted; hardy; dignified; stately.
1 other Webster entry under this spelling
Manly, adv.
In a manly manner; with the courage and fortitude of a manly man; as, to act manly.
Shades of meaning
Fernald has no entry of its own for manly; he lists it under masculine.
Where he writes about it:
Manlike may mean only having the outward appearance or semblance of a man, or may be closely equivalent to manly. — from masculine
Manly refers to all the qualities and traits worthy of a man; manful, especially to the valor and prowess that become a man; we speak of a manful struggle, manly decision; we say manly gentleness or tenderness; we could not say manful tenderness. — from masculine