clearance sale vs sales event

clearance sale and sales event both are nouns.

Word	Noun	Adjective	Verb	Adverb
clearance sale	Yes	No	No	No
sales event	Yes	No	No	No

As nouns, sales event is a hypernym of clearance sale; that is, sales event is a word with a broader meaning than clearance sale:

clearance sale: a sale to reduce inventory
sales event: an occasion (usually brief) for buying at specially reduced prices

Other hypernyms of clearance sale include cut-rate sale, sale.

clearance sale (noun)	sales event (noun)
a sale to reduce inventory	an occasion (usually brief) for buying at specially reduced prices