These words are closely related but have distinct meanings and applications. Male always refers to sex: "Jim belongs to a male choir." Manly implies possession of the most desirable qualities a male can have. Masculine refers to the qualities of a male as contrasted with those of a female. Male, manly, and masculine have the shades of meaning concerning men that female, womanly, and feminine have for women. See also female.
Dictionary of problem words and expressions. Harry Shaw. 1975.