Tогда лучше вот что почитайте. Хоть и не русского языка, и не совсем толковый словарь
но очень интересно.
Итак. Idiot: a foolish or stupid person.
To say a person is "his own man" is certainly not to insult him. To call him an idiot is quite another thing. The Greek adjective idios means 'one's own' or 'private'. The derivative noun idiotes means 'private person'. A Greek idiotes, however, was not "his own man" in the way we mean that phrase today. He was simply a person who was not in the public eye, who held no public office. From this sense came the sense 'common man', and later 'ignorant person'--a natural extension, for the common people of Greece were not, in general, particularly learned. The word was borrowed from Greek into Latin as idiota, whence French has idiote, which in turn became a loanword in English in the thirteenth century.
The milder meaning of idiot, 'ignorant person', is obsolete. But John Capgrave, in the middle of the fifteenth century, could speak of Christ's apostles as idiots and never fear the wrath of the church: "Ryght as be twelue ydiotes, sent Austin [Saint Augustine] seyth, hee meneth the apostellis, for thei not lerned were." By carrying ignorance to extremes, we arrive at the idiot who is mentally deficient. An English lawyer, Henry Swinburne, defined this idiot, in 1590: "An Idiote, or a naturall foole is he, who notwithstanding he bee of lawfull age, yet he is so witless, that hee can not number to twentie, nor can tell what age he is of, nor knoweth who is his father, or mother, nor is able to answer to any such easie question."
The word private itself, though in some uses it suggests the sign on the boss's office, has fallen to a low estate in the military sphere, where it denotes the lowest rank. Private comes from Latin privatus, which as a noun is a near synonym of the Greek idiotes. In formation the word is a past participle of privare, 'to deprive, relieve'. Privatus, used as an adjective, had already in Latin the more or less contrary connotations of our own private. It could refer to private property (cut off from the public) or to unofficial, merely individual, and thus often subordinate status (cut off from public office).
Merriam-Webster provides a free online dictionary, thesaurus, audio pronunciations, Word of the Day, word games, and other English language resources.