Greatly valued; precious:
(Obs.) High; lofty
Having a high proportion of fuel to air
(--- Informal) Excited or euphoric:
Negative, unfavorable, or disapproving:
Find another word for costliest. In this page you can discover 6 synonyms, antonyms, idiomatic expressions, and related words for costliest, like: dearest, steepest, richest, highest, worthiest and poorest.