thriftshop vs second-hand store

thriftshop and second-hand store both are nouns.

Word	Noun	Adjective	Verb	Adverb
thriftshop	Yes	No	No	No
second-hand store	Yes	No	No	No

As nouns, thriftshop and second-hand store are synonyms defined as:

thriftshop and second-hand store: a shop that sells secondhand goods at reduced prices

thriftshop (noun)	second-hand store (noun)
a shop that sells secondhand goods at reduced prices	a shop that sells secondhand goods at reduced prices