2. (n) a homeless person/layabout
3. (v) to do someone up the arse, ie. perform anal sex on them
4. (v) (brit) to like something/someone very strongly
5. (a) (brit) fit, hot, sexy etc.
2. "any spare change?"
3. "wow todd bummed me SO hard last night I won't be able to sit down for days"
4. "OMG I just totally bum chocolate ice cream!"
5. "phwoar he's so bum!"