noun
radio operator; telegraph operator; communications officer
A person who operates radio or telegraph equipment, especially in maritime, aviation, or military contexts.
彼は船の通信士として働いている。
He works as a radio operator on a ship.
遭難信号を受信した通信士がすぐに救助を要請
The communications officer who received the distress signal immediately requested rescue.
Refers to a military communications soldier rather than a civilian operator.
Compound of 通信 (つうしん, 'communication') and 士 (し, 'person in a specialized role').