efflorescence vs period of time

efflorescence and period of time both are nouns.

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

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

Other hypernyms of efflorescence include period, time period.

efflorescence (noun)	period of time (noun)
a powdery deposit on a surface	an amount of time
the time and process of budding and unfolding of blossoms
any red eruption of the skin
the period of greatest prosperity or productivity