"Do you believe," said Candide, "that men have always massacred each other as they do to-day, that they have always been liars, cheats, traitors, ingrates, brigands, idiots, thieves, scoundrels, gluttons, drunkards, misers, envious, ambitious, bloody-minded, calumniators, debauchees, fanatics, hypocrites, and fools?"
There are no more uses of "ingrate" in the book.
Show samples from other sources
And just when he had gotten it to the point of learning to eat nothing at all, the ingrate up and died.
Jane Yolen -- The Devils Arithmetic
They found out we had my father in Comfort Hill and that I rarely visited, and thus 1 was an ingrate dad-abandoner.