What does "disingenuous“ really mean in English? Any good definitions? [closed]

From Merriam-Webster:

Disingenuous Has a Roman History

Ingenous has its roots in the slave-holding society of ancient Rome. Its ancestor ingenuus is a Latin adjective meaning "native" or "freeborn" (itself from gignere, meaning "to beget"). Ingenuus begot the English adjective ingenuous. That adjective originally meant "freeborn" (as in "ingenuous Roman subjects") or "noble and honorable," but it eventually came to mean "showing childlike innocence" or "lacking guile." In the mid-17th century, English speakers combined the negative prefix dis- with ingenuous to create disingenuous, meaning "guileful" or "deceitful."

So people flipped the term ingenuous which was used to describe people who were harmless or innocent like a child. They used the dis prefix to do so. So, we have disingenuous, which refers to someone who acts very much not like a child, someone who is cunning, crafting, and destructively self-interested. It's not a hypocrite, it's someone who is not honest and knows it and is trying to hide it. Someone "lacking in candor".