watt
Concise Oxford English Dictionary © 2008 Oxford University Press:
watt /wɒt/ (abbrev.: W)
▶noun the SI unit of power, equivalent to one joule per second, corresponding to the rate of energy in an electric circuit where the potential difference is one volt and the current one ampere.
– origin C19: named after the Scottish engineer James Watt.
'watt' also found in these Oxford entries:

