from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Having a smaller proportion of alcohol than proof spirit.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Having a lower alcohol content than proof spirit.
from the GNU version of the Collaborative International Dictionary of English
- adj. Containing less alcohol than proof spirit. See Proof spirit, under spirit.
from The Century Dictionary and Cyclopedia
- Having a greater specific gravity than 0.91984: applied to alcoholic liquors.
under- + proof (Wiktionary)