refine
re.fine \ri-'fi-n\ vt 1: to reduce to a pure state {~ sugar} 2: to free
from moral imperfection : ELEVATE 3: to improve or perfect by pruning or
polishing 4: to free from what is coarse, vulgar, or uncouth 1: to become
pure or perfected 2: to make improvement by introducing subleties or
distinctions - re.fin.er n
Webster's English Dictionary