one day

one, 1 / the first in order, foremost / the beginning / the best / a kind of; one of something / (card games) an ace / unity / the bottom string of a shamisen or other Japanese musical instrument

each person

Alternative form of 一々

(rare) the first day of the month

once; one time

first, foremost, number one

one person / singleness, singularity / one's own efforts or strengths / an unmarried person, single

one defeat

all at once