auction vs auction sale

auction and auction sale both are nouns.

Word	Noun	Adjective	Verb	Adverb
auction	Yes	No	Yes	No
auction sale	Yes	No	No	No

As nouns, auction and auction sale are synonyms defined as:

auction and auction sale: the public sale of something to the highest bidder

Other synonyms of auction include vendue.

auction (noun)	auction sale (noun)
the public sale of something to the highest bidder	the public sale of something to the highest bidder
a variety of bridge in which tricks made in excess of the contract are scored toward game; now generally superseded by contract bridge

auction (verb)	auction sale (verb)
sell at an auction