regress vs abstract thought

regress and abstract thought both are nouns.

Word	Noun	Adjective	Verb	Adverb
regress	Yes	No	Yes	No
abstract thought	Yes	No	No	No

As nouns, abstract thought is a hypernym of regress; that is, abstract thought is a word with a broader meaning than regress:

regress: the reasoning involved when you assume the conclusion is true and reason backward to the evidence
abstract thought: thinking that is coherent and logical

Other hypernyms of regress include logical thinking, reasoning.

regress (noun)	abstract thought (noun)
returning to a former state	thinking that is coherent and logical
the reasoning involved when you assume the conclusion is true and reason backward to the evidence

regress (verb)	abstract thought (verb)
go back to bad behavior
get worse or fall back to a previous condition
go back to a previous state
go back to a statistical means