Often doesn't have it's own definition. Only when placed with other words it really has a meaning
1. No diggity = no doubt, for sure
2. Bomb diggity = great, awesome, the best, etc
1. "I like the way you work it. No Diggity! I got to bag it up."
(from song "No Diggity" by Blackstreet)
2. "Hey, did you get that new album yet? It's the bomb diggity!"