derich

From de- +‎ rich.

IPA^(key): /ˌdiˈɹɪt͡ʃ/

derich (third-person singular simple present deriches, present participle deriching, simple past and past participle deriched)

1. (aviation, rare) To make the air–fuel ratio (of a jet engine or a carburetor) leaner (less rich).

   Synonyms: lean, disenrich

   • 2019, Graham, Richard H., Flying the SR-71 Blackbird: In the Cockpit on a Secret Operational Mission‎^{[9780760366424]}, Motorbooks International, page 62:

     The fuel derich system on each engine protected against severe turbine over-temperature. If the engine's EGT indicator reached 860 degrees Celsius while the system was armed, the air/fuel ratio in the engine was automatically reduced (deriched).

• enrich