lab vs science laboratory

lab and science laboratory both are nouns.

Word	Noun	Adjective	Verb	Adverb
lab	Yes	No	No	No
science laboratory	Yes	No	No	No

As nouns, lab and science laboratory are synonyms defined as:

lab and science laboratory: a workplace for the conduct of scientific research

Other synonyms of lab include laboratory, research lab, research laboratory, science lab.

lab (noun)	science laboratory (noun)
a workplace for the conduct of scientific research	a workplace for the conduct of scientific research