In ancient Greek there are at least five terms that define the mass, the crowd and the multitude. One of them is omicron chi lambda omicron sigma, a concept born in the 5th Century B.C. which is used repeatedly by Thucydides as a biased synonym for delta eta mu omicron sigma. From the analysis of some of the eighteen mentions of the term omicron chi lambda omicron sigma. in his work, it is possible to reaffirm the powerful political effect of this concept in order to demonstrate, once again, the strong anti-democratic component in his work.