1. Chinese Dumpling with savoury filling often served in soup (3,3) * O * / T * * 2. Rectangular shape given to a gemstone by cutting and polishing (8) * A * U * * T * 3. Ratio of the output signal to the input signal of an amplifier, usually measured in decibels (4) * A * *
Answer is gain, NOT watt. Watt is a unit (of power) itself: watts=volts x amps..hence rules out decibels(another unit, but of sound or noise). Definitely GAIN.
Good luck.