proof spirit

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An alcohol-water mixture or a beverage containing a standard amount of alcohol, the US standard being 100 proof, or 50 percent, of ethyl alcohol by volume at 60°F (approximately 15.6°C).

from The Century Dictionary.

• noun In com., an alcoholic liquor which has a specific gravity of 0.920, and contains 0.495 of its weight, or 0.5727 of its volume, of absolute alcohol.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A mixture of alcohol and water used as a standard for distilled drinks

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a mixture containing half alcohol by volume at 60 degrees Fahrenheit