"methods of a charlatan," 1804, from French charlatanisme; see charlatan + -ism. OED describes synonym charlatanry (1630s) as "More contemptuous ... and referring more to actual practice."
Entries linking to charlatanism
charlatan n.
"one who pretends to knowledge, skill, importance, etc.," 1610s, from French charlatan "mountebank, babbler" (16c.), from Italian ciarlatano "a quack," from ciarlare "to prate, babble," from ciarla "chat, prattle," which is perhaps imitative of ducks' quacking. Related: Charlatanical.
-ism
word-forming element making nouns implying a practice, system, doctrine, etc., from French -isme or directly from Latin -isma, -ismus (source also of Italian, Spanish -ismo, Dutch, German -ismus), from Greek -ismos, noun ending signifying the practice or teaching of a thing, from the stem of verbs in -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached. For distinction of use, see -ity. The related Greek suffix -isma(t)- affects some forms.