Possible Clues:

• Wheel to turn in class
• How decay consumed this in a roundabout way
• Turn to turn in this rate
• Nonsense devoured, though it's spin
• Decay will get around to 17 across
• Turn, or turned, junk east
• Decay took this as a matter of course, in a roundabout sort of way
• Even if it starts to be bad, one might get around to having eaten it
• Go round — right round — a gallery
• Decay consumed what's round about here