A word used by a group of people who think they have started a fad, but have completely overestimated the popularity of its use and really just annoy the crap out of everyone.

A word used to define a buddy, pal or friend. Said at the end of a sentence, usually said with stress on the "der". Most commonly used in private prep schools.

a retarded person that must wear a helmet to function

a select friend, a friend you would say is special enough to be called by this term