improve or perfect by pruning or polishing
refine too much or with excess of subtlety
make more complex, intricate, or richer
attenuate or reduce in vigor, strength, or validity by polishing or purifying
reduce to a fine, unmixed, or pure state; separate from extraneous matter or cleanse from impurities
make more precise or increase the discriminatory powers of
treat or prepare so as to put in a usable condition
