refine vs fine-tune

refine and fine-tune both are verbs.

Word	Noun	Adjective	Verb	Adverb
refine	No	No	Yes	No
fine-tune	No	No	Yes	No

As verbs, refine and fine-tune are synonyms defined as:

Other synonyms of refine include down, polish.

refine (verb)	fine-tune (verb)
reduce to a fine, unmixed, or pure state; separate from extraneous matter or cleanse from impurities	adjust finely
improve or perfect by pruning or polishing	improve or perfect by pruning or polishing
treat or prepare so as to put in a usable condition	make fine adjustments or divide into marked intervals for optimal measuring
attenuate or reduce in vigor, strength, or intensity by polishing or purifying
make more precise or increase the discriminatory powers of
make more complex, intricate, or richer