Meaning
A male child, from birth to the age of puberty; but in general, applied to males under ten or twelve years of age; a lad. Sometimes it is used in contempt for a young man, indicating immaturity, want of vigor or judgment.
BOY, v.t. To treat as a boy.
Rather, to act as a boy; to imitate a boy in action. The passage in Shakespeare,in which this word is found,is supposed to allude to the practice of boys acting women's parts on the stage.
I shall See Some squeaking Cleopatra boy my greatness.