Answer:
Watts, amperes (amps) and voltage are three aspects of electricity. There are no watts or amps in a volt. Watts are equal to volts multiplied by amperes (watts = amps x volts).
If you consider the equation Watt(W)=Voltage(V)*current(I), you can see the relationship between the watt and volt. That is, in the simplest terms consistent with Ohm's Law, putting this equation in to this form, V=W/I. That is watt(a measure of Power) is directly proportional to voltage. This is the mathematical relationship so there is no watt-amp. FYI Ohm's Law shows the relationship between voltage, current and resistance. E=I*R.
(amendment) Watts are only directly proportional to voltage if the current is independent of voltage, which is unusual. For a resistive load, the current is also proportional to voltage, so W=V x (V/R) or W=V2/R or I2R