弟子 Deshi (Japanese) means a pupil, follower, or apprentice. In real life the many stars that came out of the Kitani dojo were/are the deshi of Kitani Minoru. On the other hand, in Hikaru No Go Waya is the deshi of Morishita sensei.
See also: Professionals' pupils
On, SL, the term is mainly mis-applied to regular users of SL itself. These deprived individuals are often Recent Changes Junkies who suffer from Obsessive Compulsive Wiki Editing Disorder - see also User Preferences. However, they are basically not deshi. The term does not have a general meaning of student. It describes a teacher (senior) - pupil (junior) relationship.
Bill: I thought the deshi here were deshi of the sensei of Sensei's Library. ;-)