root cellar vs excavation

root cellar and excavation both are nouns.

Word	Noun	Adjective	Verb	Adverb
root cellar	Yes	No	No	No
excavation	Yes	No	No	No

As nouns, excavation is a hypernym of root cellar; that is, excavation is a word with a broader meaning than root cellar:

Other hypernyms of root cellar include storage space.

root cellar (noun)	excavation (noun)
an excavation where root vegetables are stored	the act of extracting ores or coal etc from the earth
	the act of digging
	a hole in the ground made by excavating
	the site of an archeological exploration