The practice, behavior, or quality of being a charlatan; fraud, deception, or pretense of knowledge or skill.
From charlatan plus the suffix -ism, turning the word into an abstract noun describing the practice or system of charlatans.
Charlatanism became a serious problem in medicine before modern regulations—doctors had no license, so anyone could claim to cure diseases with worthless concoctions, making 'charlatanism' a term of serious moral disapproval!
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