A nickname borrowed from the common apple which is used to describe an extremely attractive female who easily turns red due to any kind of embarrassment or laughter.
Casper: "Hey girl, you're super cute."
Jessica: "Awww stop it! You're making me blush!"
Casper: "You're even cuter when you blush. You're a Red Delicious!"
When the previous day, or yesterday, served the sole purpose of catching up on much needed rest and sleep.
"Man, after that week-long backpacking trip I was so exhausted that I had a resterday. I feel great now though!"