A nickname usually given to amazing girls with great personalities, these girls are known to be stunningly gorgeous, beautiful inside and out, fun, out-going, spontaneous, and sexy. Shelly's are also known to be the best girlfriends and the best in bed. Shelly can be used as an adjective to describe something incredibly awesome, entertaining, and astounding.
Everyone wants a friend named Shelly!
What you did was so Shelly.
If only you were a Shelly.
That's right, Shelly is my girlfriend.