The definition of an adjective is a part of speech that is used to describe a noun. Red, tall, better and fast are all examples of adjectives.
In modern parlance, a gentleman (from gentle + man, translating the Old French gentilz hom) is any man of good, courteous conduct. A gentleman may also simply be a polite term for any man, as in indications of gender-separated facilities, or as a sign of the speaker's own courtesy when addressing others. The modern female equivalent is lady.
suitable to the male sex; characteristic or suggestive of a male; masculine; as, male courage. Male (verb) consisting of males; as, a male choir. Male (verb) adapted for entering another corresponding piece (the female piece) which is hollow and which it fits; as, a male gauge, for gauging the size or shape of a hole; a male screw, etc. Male (noun)