excavation vs cellar

excavation and cellar both are nouns.

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

As nouns, cellar is a hyponym of excavation; that is, cellar is a word with a more specific, narrower meaning than excavation:

excavation (noun)	cellar (noun)
the act of extracting ores or coal etc from the earth	the lowermost portion of a structure partly or wholly below ground level; often used for storage
the act of digging	storage space where wines are stored
a hole in the ground made by excavating	an excavation where root vegetables are stored
the site of an archeological exploration