honeymoon vs period of time

honeymoon and period of time both are nouns.

Word	Noun	Adjective	Verb	Adverb
honeymoon	Yes	No	Yes	No
period of time	Yes	No	No	No

As nouns, period of time is a hypernym of honeymoon; that is, period of time is a word with a broader meaning than honeymoon:

honeymoon: the early (usually calm and harmonious) period of a relationship; business or political
period of time: an amount of time

Other hypernyms of honeymoon include period, time period.

honeymoon (noun)	period of time (noun)
a holiday taken by a newly married couple	an amount of time
the early (usually calm and harmonious) period of a relationship; business or political

honeymoon (verb)	period of time (verb)
spend a holiday after one's marriage