Retweet

-noun

1. A twitter posting that begins with the capitalized letters "RT", and denotes the post is a copy of a previously posted tweet.

Example: "That isn't the original tweet. You can tell that it is a retweet by the way it was started."

-verb

1. the act of copying a previously posted tweet.

Example: "His tweet made me laugh hysterically. I'm definitely retweeting that one."