Word to define person with bad social skills

How would you define a person without (or with very bad) social skills?

I don't mean a totally anti-social, but one that struggles to behave in a social context, and feels awkward or out-of-place when forced to stay and talk with other people.

Maybe that would be anti-social, but not by choice... Just thinking to be rejected/avoided by others, and that keeps trying to relate to others but fails everytime.

Is there a word that could describe this? Or else, what word would be the closest and more appropriate to help explain this?

Altough some answer overlap my question this question differs from mine. This question is not about understanding others and their feelings, but rather at behaving in social context, or being marked as a weird/awkward person that's avoided by others.

Socially Inept

"Unable to judge and improvise interactions with other people in a acceptable or 'normal' manner. By a mix of being too keen or plain ignorant the socially inept seem to live in their own world exempt from who they're talking to. "

I think being socially inept could lead to being a social outcast, but the ineptitude precedes the exile.

Avoidant personality disorder. It is more than social awkwardness or an inability to learn social skills. It draws upon a severe phobia of failure/anxiety in interacting with others.

Boor is totally inaccurate as a boor is usually self absorbed in their own interests. Socially inept is extremely close but represents an ability to learn social skills at some point.

Avoidant personality disorder is nearly impossible to overcome. It represents extreme feelings of anxiety in just thinking about interacting with strangers on a social level. Most suffering from this disorder can still interact with people in a work setting. This is the norm as well for those considered as nerds, etc. In this type of setting, Sufferers can rely on intelligence to guide their words to solve problems or interact peers. In a social setting, however; the anxiety sets in, sufferers feel uncomfortable and withdraw.

Doing some reaserch over the net, I think I've found what I was looking for.

I believe the term social outcast would be the most appropriate word to describe what I asked previously, so I'm adding my own answer here.

I'm quoting here a piece of definition that is not very "formal", which doesn't come from a dictionary but rather from "urbandictionary.com":

A loner or social outcast is a person rejected by their peers because they are different, strange, inept or misunderstood. They are ostracized, shunned, avoided, excluded, and generally unwelcome. They are victims of bullying, character assassins and scapegoats.