伍つ[itsutsu] five
伍長[gochou] corporal
卒伍[sotsugo] rank and file
落伍[rakugo] dropping out of
落伍者[rakugosha] dropout

隊伍[taigo] ranks of troops
伍を重ねる[gowokasaneru] to double the ranks
先頭伍[sentougo] leading file
伍する[gosuru] to rank with

一隊[ittai] party
掩護部隊[engobutai] covering force
横隊[outai] rank
火力支援部隊[karyokushienbutai] fire support element
海兵隊[kaiheitai] Marine Corps

外国部隊[gaikokubutai] overseas (military forces)
格闘戦部隊[kakutousenbutai] shock troops
楽隊[gakutai] band
艦隊[kantai] (naval) fleet
機動隊[kidoutai] riot police