Definition of derate in English:



[with object]
  • 1British (under the former rates system) remove part or all of the burden of rates from (a property or business)

    ‘I shall shortly announce the level of industrial derating for next year’
    • ‘The shares have fallen 64 per cent since January 2001, due to the derating of the telecom sector and a delay in the deregulation of the British directory assistance market.’
    • ‘That's not acting as a prop for the share price. The shares have been derated.’
    • ‘The derating may be overdone, if recent reports of bids by management teams at the three companies are anything to go by.’
    • ‘We believe that investors should be investing in growth stocks following the significant derating of many of these stocks over the last 15 months.’
  • 2Reduce the power rating of (a component or device)

    ‘the engines were derated to 90 horse power’
    • ‘The thrust of the two turbofan engines on underwing pylons would be uprated or derated to reflect the number of seats, allowing the same engine to be used on all three versions.’
    • ‘If the breakers must touch each other, they should be derated to 80% of their normal amperage rating.’
    • ‘If the circuit breaker is mounted in a horizontal plane, derating is required.’
    • ‘The transmission derates the outputs of both engine types to 450 shp for takeoff and 380 shp for max continuous thrust.’
    • ‘He said the design is basically a 9,000-lb-thrust engine, heavily derated to specific airframe power requirements.’