(mechanics) fluid mechanics

sewer installed by 都道府県 (todōfuken, “a prefecture”) in order to treat sewage from two or more 市町村 (shichōson, “cities, towns, and villages”)

dragon

one day, 24 hours / the daytime, the period from dawn until dusk / (figuratively) a short period of time / one day, someday, an unspecified day / the first day of the month

(linear algebra) positive-definite matrix

(linear algebra) positive-semidefinite matrix

(literally) one side / everywhere, all around, the whole area / one viewpoint, one opinion or way of thinking / the front page of a newspaper

Alternative spelling of 花一匁

(idiomatic, proverb) be quick on the uptake, understand the whole situation from just a few clues

a traditional Japanese children's game that is similar to the game red rover