Wiktionary
derating
n. The act by which something is derated. vb. (present participle of derate English)
Wikipedia
Derating
This article is about electronics. For the adjustment of engines for longer engine life see engine tuning.
In electronics, derating (or de-rating) is the operation of a device at less than its rated maximum capability in order to prolong its life. Typical examples include operation below the maximum power rating, current rating, or voltage rating.