An army or the armed forces — organized military troops of a nation or organization.
その国は外敵に備えて軍を増強した。
The country strengthened its military forces to prepare for foreign threats.
彼は二年間軍に勤務した経験がある。
He has two years of military service experience.
演習のために大規模な軍の動員が行われた。
A large-scale mobilization of troops was carried out for the exercises.
Military authorities or leadership — the hierarchical organ of the military (often used in political contexts).
軍の指導部が政府に圧力をかけたと報じられた。
It was reported that the military leadership exerted pressure on the government.
戦前は軍が政治に強い影響を及ぼした。
Before the war the military had a strong influence on politics.
A team or group — sometimes used figuratively or colloquially to refer to a collective or troupe.
今年のイベントでは女性軍が活躍した。
At this year's event the women's team played an active role.
地元の若手軍が大会で好成績を上げた。
The local group of young players achieved good results in the tournament.