underproof

[ uhn-der-proof ]
/ ˈʌn dərˈpruf /

adjective

containing a smaller proportion of alcohol than proof spirit.

Origin of underproof

First recorded in 1855–60; under- + proof

British Dictionary definitions for underproof

underproof
/ (ˌʌndəˈpruːf) /

adjective

(of a spirit) containing less than 57.1 per cent alcohol by volume