late 14c., "male human being; male fish or land animal; one of the sex that begets young," from Old French masle (adj.) "masculine, male, adult," also used as a noun (12c., Modern French mâle), from Latin masculus "masculine, male, worthy of a man" (source also of Provençal mascle, Spanish macho, Italian maschio), diminutive of mas (genitive maris) "male person or animal, male."
Male, matching female, applies to the whole sex among human beings and gender among animals, to the apparel of that sex, and, by figure, to certain things, as plants, rimes, cesuras, screws, joints. Masculine, matching feminine, applies to men and their attributes and to the first grammatical gender; a woman may wear male apparel and have a masculine walk, voice, manner, temperament. [Century Dictionary, 1895]
late 14c., "pertaining to the sex that begets young," as distinguished from the female, which conceives and gives birth, from Old French male, masle "male, masculine; a male" (see male (n.)). Mechanical sense, used for the part of an instrument that penetrates another part, is from 1660s. Meaning "appropriate to men, masculine" is by 1788. Sense of "composed or consisting of men and boys" is by 1680s.