(Adj) A 'bumwindow' occurs when someone is sitting in a chair that has a hole in the back, most commonly in a school assembley, and has their arse hanging out so you can clearly see it through the gap in the chair. Urgh.

A Bloomer is someone with a bright outlook on life who is optimistic in nature. Bloomer's frolic in every opportunity to be happy and try to make the most out of life. The opposite of a Bloomer is a Doomer. The term Bloomer originated specifically as a counter to the Doomer on sites especially like 4Chan.