Simply add the first letter and the definition to get your answer.
-1. G + To speak in a harsh voice = To understand. 5 letters
-2. A + Empty space = To prevent something. 5
-3. P + It is uncomfortable and you want to scratch it = A dark sticky substance that is made from tar. 5
-4. D + Not cooked = To figure out by using power of reason. 4
5. C + Stirred up small waves = Unable to walk. 7
-6. C + Roadway connecting different levels = Sharp pain. 5
-7. D + To utter aloud the printed words = Great fear or anxiety. 5
-8. R + Every one = To stretch out or extend. 5
-9. G + A stretcher = To sparkle. 6
-10. S + The highest or best point = Say words out loud. 5