1. uncertain or not fixed   infinitesimal   determinate   carcinogenic   indeterminate   Hint Half-n-half Clue   2. arranged in gradations (e.g., of difficulty).   infinitesimal   graduated   biennial   derivative   Half-n-half Clue   3. dangerous or risky.   carcinogenic   impenetrable   hazardous   embryonic   Half-n-half Clue   4. distinct or unconnected.   discrete   biennial   carnivorous   analgesic   Half-n-half Clue   5. pertaining to the brain.   derivative   centrifugal   abrasive   cerebral   Half-n-half Clue   6. herb-eating or vegetarian.   generic   cerebral   herbivorous   anthropoid   Half-n-half Clue   7. pertaining to the art of gardening.   cosmic   congenital   chronic   horticultural   Half-n-half Clue