one part

一日経: dead memorial service where many gather to transcribe a sutra in one day

水中: in the water / 水柱: column of water

一日中: all day, throughout the day, sunrise to sunset, all around the clock

一輪車, 1輪車: a unicycle

一塁手: a first baseperson; a first baseman; a first basewoman

一部始終: the whole story

(military) mortar (weapon)

(military, historical) a specially-organized attack force, the most notable being the kamikaze (suicide bombing) attack corps during World War II

an attack