The term is an eponym, a word derived from a person's name. It honors James Watt (1736–1819), whose improvements to the steam engine were fundamental to the Industrial Revolution. The adoption of 'watt' as the unit of power in the International System of Units (SI) in 1889 formalized his legacy into scientific terminology. Thus, a personal name became a universal standard measurement for the rate of energy conversion.

This is a proper noun adopted as a standard unit. It is derived from the surname of James Watt, the Scottish engineer.