R2-D2

It means this or something else was of little value.

Picture this, R2-D2 making a wish.

D2S

destined to succeed

bro i rate the hustle, your really d2s.

D2

The second dump in a day.

Todd rubbed his hands all excitedly because he had a D2 brewing.

D2

Shorthand for 'designated driver.' The person who escorts you to the club, drinks lightly if at all, and helps drive you home after a long night of cirrhotic frivolity. D2s are occasionally given special treatment by bartenders for their services, such as offering snacks and non-alcoholic beverages to dedicated D2s.

Person 1: "Hey, can you be my D2 tonight?"
Person 2: "Sure! I charge $13 per hour, plus $50 if you vomit in my car."
Person 1: "What? Why are you charging me just to-- ...oh."