Present participle: the ongoing process of combining two different frequencies to produce new frequencies; the method used in radio receivers.
Heterodyne plus the present participle suffix -ing. The term became standard in electronics and radio engineering vocabulary in the 20th century.
Heterodyning is happening right now in your phone, WiFi router, and Bluetooth devices—it's the invisible foundation of wireless communication, yet most people have never heard the word despite using the technology constantly.
Complete word intelligence in one call. Free tier — 50 lookups/day.