1. Full house = Over or near 20% bodyfat with no visible muscle definition and only a hint of separation between major muscle groups if those groups are very large. Basically a person in this state could be confused for a football linebacker. If you're higher than this bodyfat percentage, you'd be considered overweight/obese.
2. Hard = Some muscle separation appears between delts and upper arm. Abs are still not visible. Approximately 15% bodyfat.
3. Cut = More muscle separation appears particularly in the chest and back, outline of the abs begins to appear slightly. Approximate bodyfat level = 12%
4. Defined = Muscle separations get deeper in the arms, chest, legs and back, and abs appear when flexed. Approx. bodyfat level = 10%
5. Ripped = Abs are clearly visible all the time, vascularity in arms is prominent, chest and back separation is obvious, and face is starting to appear more angular. Condition can be held indefinitely. Approximate bodyfat level = 7-9%
6. Shredded = Striations appear in large muscle groups when they are flexed. You look small in clothes, but look fantastic when you're not. Vascularity appears in lower abdomen and in the legs. Condition can be held for several days with careful dieting. Competitive bodybuilders often aim for this state for competition day. Approximate bodyfat level = 5-7%
7. Sliced = Muscles and tendons begin to appear in the face when chewing, striations appear everywhere and vascularity appears everywhere. Bodyfat levels are close to 3% and subcutaneous water levels are near 0. Condition can only be held for a few hours at a time. Not a healthy condition to stay in due to lower water level.
Examples with pictures here:
Examples of Bodyfat levels
This is no exact science though, it may vary from person to person.
But at +20%BF, you won't see any abs, it doesn't vary that much...