Question

define 1 watt of power.

Answer 1

The watt (symbol: W) is a unit of power. It is an derived unit in the International System of Units (SI) defined as 1 joule per second[1] and can be used to quantify the rate of energy transfer.

Answer 2

1 watt is the power of an agent,  which does work at the rate of 1 joule per second.