Possible Clues:

• Review unfairly
• Sell short
• 'Up to seven, by the sound of it, if you think that's too little (9)'
• Have too low an opinion of
• Make too low an estimate of
• Not one over the eight, by the sound of it?
• Make too little of the way to do wrong at being in the nude
• Not value enough
• Not one over the eight, by the sound of it
• Perhaps did not eat too much, but one may put a low estimate on that