liar vs fabricator

liar and fabricator both are nouns.

Word	Noun	Adjective	Verb	Adverb
liar	Yes	No	No	No
fabricator	Yes	No	No	No

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

Other hyponyms of liar include false witness, perjurer, fibber, storyteller.

liar (noun)	fabricator (noun)
a person who has lied or who lies repeatedly	someone who tells lies