A memeber is an individual on an internet forum who does little more than post incredibly old and over-used meme's. The memeber typically believes themselves to be amazingly witty, but is generally regarded as being borderline retarded.
John: April, did you know that I'm an elected memeber of 9GAG
Jones: What are you again?
John: Stop laughing. A memeber is a person who's part of a meme page's admin team.