A 22oz bottle of beer (commonly used by microbreweries) or a 1.5liter bottle of wine (also known as a magnum).
I drank an entire bomber of something called Steel Rail Extra Pale Ale once. By the end of the meal I was listing heavily to the left and serenading my parents with a very weedy rendition of "American Pie".
In rock climbing, a hold that is really big or deep or otherwise so good that it is "bomb-proof". Can also be used of equipment that is so good as to be infalliable.
"I was climbing She Don't Use Jelly (5.10a), and I about decked five times before I got to that bomber jug on the second pitch."
Scottish term for a round hole in an item of clothing burned by falling ash from a cigarette (or cannibis joint) of which you were smoking.