refinement

a highly developed state of perfection; having a flawless or impeccable quality; "they performed with great polish"; "I admired the exquisite refinement of his prose"; "almost an inspiration which gives to all work that finish which is almost art"--Joseph Conrad

the result of improving something; "he described a refinement of this technique"

the process of removing impurities (as from oil or metals or sugar etc.)

a subtle difference in meaning or opinion or attitude; "without understanding the finer nuances you can't enjoy the humor"; "don't argue about shades of meaning"

the quality of excellence in thought and manners and taste; "a man of intellectual refinement"; "he is remembered for his generosity and civilization"