A hermit is a person who lives to some greater or lesser degree in seclusion and/or isolation from society.
The life of a hermit is usually very lonely, they don't like going out and seeing other people/friends and prefer to stay indoors.
A hermits best friend is usually his computer or television. They usually find sanctuary in games such as Guitar Hero or World of Warcraft.
Peter "Hey Sango you haven't come out in weeks, how about a beer"
Sango "Errrr, sorry man I'm gona stay in and play Guitar Hero"
Peter "Come on I will buy you a drink haven't seen you in weeks you hermit"
Sango "Noo thanks, kinda busy" *loud guitar hero strumming in the background*