Difference between "лгун" and "лжец"

Question

Speaking of words "лгун" and "лжец", which to me as a native speaker sound quite interchangeable, which form is used more often? And which of these words of such close origin and meaning can be considered the "original" form. Can we say that one of these words has been in use longer than another? At last, are there any connotational and stylistic differences between these two forms?

Answer 1

Although most dictionaries I checked regard these two as full synonyms, there is a difference in word usage. Толковый словарь Ушакова says, "ЛЖЕЦ. Человек, заведомо говорящий ложь; то же, что лгун. Он лжец и клеветник." and Толковый словарь Ефремовой says, "ЛГУН. Тот, кто постоянно лжёт или привык лгать."

So лжец is a liar who lies with a malicious intent, pursuing his benefit at the expense of others. His lies are harmful. Calling someone лжец is right at par with calling them a traitor or a coward.

Лгун is a liar who lies out of habit, not specific intent to harm someone or gain benefit. While лжец accuses someone of specific facts and actions, лгун refers to a character trait. It even has a diminutive form лгунишка, most commonly describing children who lie. But it still bears negative connotation, unlike выдумщик or фантазёр.

There are a LOT of other synonyms, if you want to go deeper: врун, враль, брехун, обманщик...

Answer 2

«Лгун» is softer. Almost harmless word. For example see this movie.

«Лжец» is more offensive. It may be adulterer or swindler.

Answer 3

Лгун is somebody who did tell lie.

Лжец is somebody who tells lies often, permanently or sometimes.

Answer 4

лжец is used more often according to personal feeling and google search results :)
You can't pick one as original, because they are synonims with different roots, each form used in different cases.

корень слова лгун: -лг-; суффикс: -ун-;
корень слова лжец: -лж-; суффикс: -ец-.

in my humble vision:
лгать - to lie
лгал(а) - he(she) lied
лжец, лгун - liar
лгунья - (female) liar
лже-(что-то) - false (something)
лживо - falsely
ложный - false
ложь - a lie

see verb ЛГАТЬ in Толковый словарь Даля for reference of usage in old russian (some forms are obsolete):
http://vidahl.agava.ru/P091.HTM

nearly all russian dictionaries for лжец:
http://dic.academic.ru/searchall.php?SWord=%D0%BB%D0%B6%D0%B5%D1%86&stype=0