Etymology See proof. Most hard liquor sold at retail in the United States is between 80 and 95 proof (40 to 47.5% by volume); higher proof alcohol is usually bootlegged.
1941 February 9, "The 'Hated Hun'—Then and Now", The New York Times, In those days a Hollywood hero had to be 110 proof....
2002 February 1, "With a Sister Tour, 'O Brother' Family Expands", Boston Globe, Then I was wondering who this Bob Dylan was who wrote this great song, and then I was going deeper and deeper to the stuff that's 110 proof.
1 more example
Attention must be paid to Dr. Ron Paul, the 110-proof libertarian in the Republican race.2007 December 12, Howard Fineman, “Starting From Scratch”, in Newsweek:
2
US Used other than figuratively or idiomatically: 55% alcohol by volume.
110 proof
adv
Etymology See proof. Most hard liquor sold at retail in the United States is between 80 and 95 proof (40 to 47.5% by volume); higher proof alcohol is usually bootlegged.
1
Intensely; strongly.
The crowd which jams the grandstands... constitutes the most informal assemblage in the world. This crowd is 110 proof democratic and unconventional. Judge, subway guard, doctor, banker,..., laborer—they can all sit in the same row....1920 April 11, “Baseball Park, a Stronghold of Free Speech”, in The New York Times: