いっつう 一通 Common word LinksSentence search for 一通Sentence search for いっつうKanji details for 一 and 通Edit in JMdict Noun1. one copy (of a document); one letter2. one-way trafficAbbreviation, See also 一方通行3. pure straight; winning hand containing nine consecutive tiles of the same suit (i.e. 1-9)Mahjong term, Abbreviation, See also 一気通貫 いっきつうかん, sometimes written イッツー Discussions Log in to talk about this word.