zhǔ​jī

lead aircraft

主机 (主機) zhǔ​jī
lead aircraft noun
the principal aircraft in a military formation, usually piloted by the flight leader

In the flight formation, the two wingmen must closely follow the lead plane's route.

host noun
the central processing unit of a computer system, a server, or a network host

Please connect the keyboard and mouse to the computer tower.

main engine noun
the primary engine or power unit of a ship, vehicle, or mechanical system

The ship's main engine is running at full capacity.

Frequency

Movie subtitles
4.08 per million appears in 1% of films
Written text
8.27 per million

Sources

Definitions
CC-CEDICT