From un- + valuable.
unvaluable (comparative more unvaluable, superlative most unvaluable)
- (obsolete) Invaluable; beyond price. [16th-18th c.]
- 1603, John Florio, translating Michel de Montaigne, Essays, II.4:
- I kon him thanks that he hath had the hap to chuse, and knowledge to cull-out so worthy a worke, and a booke so fit to the purpose, therewith to make so unvaluable a present unto his Countrie.
- (rare) Not valuable; having little value. [from 17th c.]