a word used to notify other people of how unlucky/unaccommodating the events surrounding you or another really are. usually used with the adverb "so" with emphasis placed on the 's' and a tonal upstep with the final syllable of the phrase.
shorya: nothin man, just had a math test
felix: o shit how wus it
shorya: sooooo bummy
Hey where's your boyfriend?
Oh, he's just out with some of his friends
Careful now you don't want him out with some Bummie's down the lane
It is also polite and acceptable to enquire after witnessing a bummy how many pairs of shorts the bummy artist was wearing before you dive in.
Not to be confused with an old man who writes books under the pseudonym 'Bummy'