In her son's lifetime she had, for his sake, condoned the mesalliance, but it was impossible for the stately chatelaine and her low-born daughterin-law to live in peace under the same roof.
We see that men of birth and wealth often allowed themselves a strange licence in dealing with their low-born fellow-citizens.
The antithesis is not exact; we expect either "boy and mature man" or "low-born and high-born."
Hence comes the modern use of the word for a low-born or vulgar person, particularly one with an unpleasant, surly or miserly character.
He did so, and then governed like an evil-disposed boy - indulging the merest animal passions, listening to a small camarilla of low-born favourites, changing his ministers every three months, and acting on the impulse of whims which were sometimes mere buffoonery, but were at times lubricous, or ferocious.