adj, verb ·Rare ·Advanced level

Definitions

Verb

1. 1
   To proof insufficiently.

Adjective

1. 1
   Having a lower alcohol content than proof spirit. not-comparable

Antonyms

All antonyms

overproof

Etymology

From under- + proof.

Related phrases

proof spirit

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.