A gift (preferably jewelry) you give your girlfriend hoping she won't notice you still didn't put a ring on it.

A hush ring is an engagement ring given with no foreseeable intention of marriage. It is usually given when a couple has been together for several years (usually with children) and the woman nags the man about getting married.

When you're in a relationship but you always have a side piece

Being quiet for a period time.

When some jive-ass turkey tries to talk over you, you lay down a tart "NIGGA HUSH!"

To keep quite on something. Has the exact same meaning and is just another way of saying down low.

To remain secretive regarding a certain topic.