military doctor; military surgeon
Refers to a physician or surgeon serving in the armed forces. The term is neutral and used in both historical and modern contexts.
He was dispatched to the battlefield as a military doctor.
Rigorous training is required to become a qualified military doctor.
After studying medicine, he became a military doctor.
He went to the front lines as a military doctor.
軍人 refers broadly to any member of the armed forces, whereas 軍医 is specifically the medical officer among them.
Compound of 軍 (military) and 医 (doctor). The reading ぐんい is a straightforward on'yomi combination.