Used other than figuratively or idiomatically: see なに, これ.

何者: someone; anyone / 何物: what

Nothing

all day

whatchamacallit, X

the first day of the month (solar or lunar calendar)

(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)

to squint