An individual who is not widely embraced by their peers for various reasons. This lack of acceptance is not always due to outright rejection, but often times from being in unfamiliar surroundings (in which case it usually passes), having a mutual lack of interest, common ground, or initiative.
Social skills definitely have something to do with it, but these are hard to quantify since there are a variety of ways that people relate to others, many of them with considerable success. It really is a matter of whether or not you have found your Feng Shui (figure of speech) in relating to others and have that developed that special "It". "It" is not a given thing (people in circumstancial isolation, such as prison or homlessness, lose their social skills foremost), but comes from
1. Confidence in self-exposure,
2. Practice and Interaction,
3. Analyzing Mistakes
The idea that social skills are naturally endowed stems from a certain type of personality (extrovert) that gravitates toward those three, but anybody who isn't One Hundred Percent happy with being completely alone can become comfortable with these habits.
Don't get rid of that vivd imagination and dynamic mind just because it's an internal trait, but share it with other people in an engaging (meaningful to them) way, and good results can be expected. If not, the problem might be in your environment or with the individuals that surround you. You don't have to be slave to the social structure, but that's no reason to be a slave to lonliness.
Followers of Christ: This issue brings up a responsibility on our part. The stone that the builders rejected becomes the cornerstone, and those who aren't sick have no need of a physician. Just like any other social group, we are also sinners and we tend to exclude others. The only difference with us is that we just happen to be on celestial parole, which is a given privelige, not a hard-earned quality. Remember that we are intended to be recognized for our indescriminate love, not for being so much holier than thou, so be a neighbor to whoever needs it, especially those who are considered lowly in whatever way.
Also realize that "Go forth and make discliples of all nations..." is not a comission to ram your faith down someone's pee-hole and give a Holy "Screw You" to those who don't accept, but an urging to offer a simple invitation: "Will you be a part of this good thing I've found?" Good luck, but remember: Far beyond how many converts you attract is how fervently you have loved your neighbor.
"...if I have not loved, then I am nothing." ~Paul The Apostle
Ridiculing an outcast is like stealing from the desitute.