(literary) one day, 24 hours / (literary) the daytime, the period from dawn until dusk / (literary) (figuratively) a short period of time

(obsolete) one day, 24 hours / (obsolete) the daytime, the period from dawn until dusk

(rare, obsolete) (all senses appear to be identical as for hitohi above)

Alternative form of 一々

all day

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