1) British slang for money 2) Gain confidence 3) Medium bra specification 
(Back UP) A backup file of the IFO file on a DVD, containing the information about the track, organization, menus, chapters, and subtitles on the disk. It is used as a redundant way to access information usually accessed by an IFO, in the event the disk is scratched or otherwise damaged.
Bup is British slang for a slice of bread and butter.