hour vs half-hour

hour and half-hour both are nouns.

Word	Noun	Adjective	Verb	Adverb
hour	Yes	No	No	No
half-hour	Yes	No	No	No

hour (noun)	half-hour (noun)
distance measured by the time taken to cover it	a half of an hour
a period of time equal to 1/24th of a day
clock time
a special and memorable period