derate
/diːˈreɪt/verb
with obj.
1
- Brit. (under the former rates system) remove part or all of the burden of rates from (a property or business)〈英〉（根据以前的税收制度）减免（财产, 公司）的税。
2
- reduce the power rating of (a component or device)降低（元件或设备）的额定功率：
the engines were derated to 90 horse power.
发动机的额定功率被降到90马力。