Things said under the influence of alcohol reveal true beliefs not expressed when sober.

Alternative form of in wine, there is truth

(logic) A variation of a truth table in which any node (representing a statement) has branches if and only if other statements (true or false) may be derived from it

simple past tense and past participle of ground truth

The absolute truth; used as an emphatic asseveration that one is not lying.

(obsolete) An honest and truthful person.

(obsolete) Exposing the truth; revealing; illuminating.

plural of grain of truth

(idiomatic) Any facts or true statements at all. / (idiomatic) A small piece of true or useful information.

(politics) A group of people who attend political meetings etc. in the guise of ordinary citizens in order to promote a particular viewpoint.