1. to hold open (Mostly for doors, but also used in a figurative sense of holding the hands open for handouts.)
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Opposite (closest): zuhalten
2. to stop (In the sense of stopping something from happening or someone from doing something. Think, super villains or technical progress.)
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3. to slow down, to hold up (In the sense of holding up someone, stopping them from progressing. Also used reflexively for contexts of (not) delaing with something - "sich+Acc aufhalten mit")
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4. to be/stay at a place ("sich+Acc aufhalten", sounds a bit formal.)
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