[chj-anh-TEE] (a.) In formal speech, a genteel person has the qualities of a gentleman, a person of noble birth. The word is an anglicized version of the French gentil, which means nice. The British did this often; in order to aid pronunciation, they simplify the spelling of borrowed words. "Wait, the last syllable of gentil is pronounced -tee with a silent L? Nonsense, we'll just spell it with two Es and speak that L too! Genteel: that's much better." Within a century, genteel was squeezed out of common usage in favor of gentle (think of the theater/theatre debate). But it wasn't just adjective that was borrowed: gentleman is a cognate of the French gentilhomme, a simple switch: gentle for gentil and man for homme.
So, you see, a true gentleman would be incapable of insulting a woman, not only because of his noble birth but because he's a nice man.