April Fools' Day

a female given name

(mahjong) completing a winning hand by drawing the final tile before reaching the dead wall

(mahjong) completing a winning hand by drawing the final tile before reaching the dead wall, worth 1 翻 (han, “double”)

(mathematics) geometrical

"Historical kana usage", a prescriptive method of using kana to write Japanese. Devised in the Edo period by Keichū (契沖) and taught in schools until 1946, it aims to be etymologically faithful and reflects earlier stages of the language (Heian period and earlier).

humanitarian

hostile takeover

experimental study

impractical; unpractical