Hang is a word with several common meanings:

1. To attach something at the top so the rest of it drops freely downward. You hang a picture on the wall with a nail, or hang your coat on a hook. Wet laundry hangs on a clothesline to dry. A chandelier hangs from the ceiling. The past tense of this meaning is hung.
2. To spend time in a relaxed, informal way. When you hang out with friends, you're spending time together without any particular plan: maybe talking, playing games, or just being together. You might hang around after school waiting for your ride, or hang at the park on Saturday afternoon.
3. To stay suspended in the air. Fog hangs over a valley on a cool morning. The smell of popcorn hangs in the air at a movie theater. A question can hang in the air when nobody answers it right away.

The word appears in many expressions: hang in there means to persevere through difficulty, hang on means to wait or to grip tightly, and getting the hang of something means learning how to do it well. If you can't quite get the hang of a yo-yo trick, you haven't figured out the knack yet.