I know that 込む on its own means something like "to be crowded." The verb 飛び込む (to jump into) looks to be derived from 飛ぶ which I think means "to fly" and the 込む ending. I've seen several other verbs like this lately, but cannot think of any others at the moment.
To end the rambling, I'd like to know what, if anything, the -込む does to a verb.
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