(linguistics) diphthong

2-step authentication

a digastric muscle

(grammar) The Classical Japanese bigrade verb conjugation class, consisting of the two subclasses of 上(かみ)二(に)段(だん)活(かつ)用(よう) (kami nidan katsuyō, “upper-bigrade conjugation”) and 下(しも)二(に)段(だん)活(かつ)用(よう) (shimo nidan katsuyō, “lower-bigrade conjugation”)

double-pane window, found especially in Hokkaido and Tōhoku as cold-proofing

a Classical Japanese adjective with シク活用 (shiku-katsuyō, “shiku-inflection”)

double dipping

(video games) new game plus

(Internet) redistribution

五日 (itsuka, go-nichi, “fifth (5th) day”) / 十日 (tōka, jū-nichi, “tenth (10th) day”) / 十五日 (jūgo-nichi, “fifteenth (15th) day”) / 二十日 (hatsuka, nijū-nichi, “twentieth (20th) day”)