Is the adjective “vain” considered offensive when applied to a person?

Question

I am given to understand by the Chambers Dictionary and Webster's that vain can be understood as thoughtless, empty-headed, useless, which all sound rather strong to me. Is it likely that a native English speaker takes offence at the following phrase?

You are vain.

If not, does the word have any potentially dangerous usages?

Answer 1

The New Oxford American Dictionary’s definition makes it quite clear that it indicates disapproval (“excessively high opinion”):

vain (adjective)
having or showing an excessively high opinion of one's appearance, abilities, or worth: their flattery made him vain.

Answer 2

Vanity is one of the seven deadly sins. So when you accuse someone of being guilty of a cardinal sin you are rebuking them for a serious flaw in their character.

By the way, you are greedy and lustful.

Oh, I didn't mean you.

Answer 3

As far as I know, vanity is a negative trait in any cultural context. And thus, "vain" is an insult to anyone who understands the word.

It is often used as quite a mild insult, I think (like a lighter, relatively benign form of arrogance), but can also be used a quite harsh description.

I don't know about "dangerous", but I would advise against using the term unless you're trying to call someone vain (obviously)

Answer 4

Vain does not mean thoughtless, empty-headed, or useless. It expresses excessive pride which is considered a negative character trait. So yes, many people would be offended if you told them they were vain.

Answer 5

Well, vain means what it means. Whether it's offensive or not depends on the cultural context of the addressee. I would say that it is usually offensive in British and American culture to describe someone as vain, but that's a sociological rather than linguistic observation.