1. one's body; one's person
彼の身に何か起きたの？Did something happen to him?
2. oneself; one's appearance
3. one's place (in society, etc.); one's position
お世話になってる身ですから。After all, I'm the one being looked after here.
4. main part; meat (as opposed to bone, skin, etc.); wood (as opposed to bark); blade (as opposed to its handle); container (as opposed to its lid)
この魚は身が柔らかくておいしい。This fish has soft, tasty flesh.