One.

Zero.

Looking up the definition of liar in the dictionary, it states; 'a person who tells lies'. Since this is plural, then I think the answer must be 2. Maybe this means that as long as you stick to the same lie, you can tell it as many times as you like and still not be a liar.

Logically, the answer would be one. But there's a problem with the question from a philosophical standpoint: the problem is that it attributes identity based on characteristics. This is an "error of common sense": the identity of things isn't actually defined by their characteristics, it's defined by being distinguished from their "other". So a cat is defined by being not-everything-but-the-cat, it's not defined by having a tail, fur, or any other specific characteristic. This mistake is the cause of many arguments, because we make the naive presumption that CATEGORY equals IDENTITY. In other words, if someone belongs in the CATEGORY "liar", that doesn't give them "liar" as a definition of their identity: it's not the thing which distinguishes them from all other things. So it's not really true that someone who tells a lie IS a liar, if you mean "lying defines their identity". It just means they can be sorted into the "liar category" if there's some need to classify. This might seem like just being picky about semantics, but it's actually crucial to the issue of human identity, which is crucial to many of the problems we humans have trouble solving: for example, a teenager makes an embarrassing mistake in public, and decides "I am a loser", because only losers would make that mistake. Having defined his identity this way at a deep level, he now spends the next 10 years trying to overcome "being a loser"... wanting to change his self-definition. Of course, none of this effort would be necessary if not for the original mistake of forming the subconscious belief "doing that thing equals I AM a loser". So this kind of error is serious stuff.

How many unlawful killings does it take to make a murderer?

only one lie will make a liar.

If you lie, you have made yourself a liar but you don't have to stay a lair forever. If you stop lying and don't do it again, and you are sorry about lying you can become a truth teller. In one sense liar is a descriptive noun but in another it is just a label. Once you stop, and regain your good name, the label can change.

Even after the only one lie, if it hurts somebody

I don't know, I am still trying to pack the pickled peppers and my woodchuck wouldn't.

To make a liar what? Wash your car? Give you money? Stop lying?

One lie makes a person have to work to earn the trust of his peers once more. Personally , I prefer not to label people, everyone changes as they grow.

one

its not how many lies, its the severity of the lie, on average humans tell 48 lies a day, lies make the world go round, people need little white lies, its the big fat nasty lies that destroy character, its when you tell those, you are considered a ''liar'' in my book anyways

1 one lie and you are a lier.

one like if you kill someone once...your a murderer...if you steal something once...your a theft...

Three.

Some people would say that, strictly speaking, a person only has to tell one lie. But since painting a room in your house doesn't make you a painter by trade, I think lying has to be habitual before you can become a liar.

one big one would do

Oh, I don't know. How many nails to make a carpenter?

one. Once you lie, it's over. If you keep on, then you could be called an habitual liar.

One, I suppose.

The very first one.