ななさんいちぶたい ７３１部隊 LinksSentence search for ７３１部隊Sentence search for ななさんいちぶたいSentence search for 七三一部隊Kanji details for 部 and 隊Edit in JMdict Noun1. Unit 731 (biological warfare unit of the Japanese Imperial Army)Historical termOther forms七三一部隊 【ななさんいちぶたい】 Discussions Log in to talk about this word.