While sometimes when people refer to themselves as a bottom it can be related to sex, some people also use it to describe themselves as a more submissive, shy, quiet person, not in sexual way.
It can also be used as a term that means that in a relationship, they wouldn't be the one to "carry" it. But is can mean different for everyone
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.