credence n.

early 13c., "the Creed in the Church service," from Latin credo "I believe," the first word of the Apostles' and Nicene creeds, first person singular present indicative of credere "to believe," from PIE compound *kerd-dhe- "to believe," literally "to put one's heart" (source also of Old Irish cretim, Irish creidim, Welsh credu "I believe," Sanskrit śrad-dhā- "faith, confidence, devotion"), from PIE root *kerd- "heart." The nativized form is creed. General sense of "formula or statement of belief" is from 1580s.

"an Italian sideboard," 1883, from Italian credenza, literally "belief, credit," from Medieval Latin credentia (see credence).

The same evolution that produced this sense in Italian also worked on the English word credence, which in Middle English also meant "act or process of testing the nature or character of food before serving it as a precaution against poison," a former practice in some royal or noble households. Because of that, it also meant "a side-table or side-board on which the food was placed to be tasted before serving" (mid-15c.); hence, in later use, "a cupboard or cabinet for the display of plate, etc." (1560s). These senses fell away in English, and the modern furniture piece, which begins to be mentioned in domestic interiors from c. 1920, took its name from Italian, perhaps as a more elegant word than homely sideboard.

Proto-Indo-European root meaning "heart."

It forms all or part of: accord; cardiac; cardio-; concord; core; cordial; courage; credence; credible; credit; credo; credulous; creed; discord; grant; heart; incroyable; megalocardia; miscreant; myocardium; pericarditis; pericardium; quarry (n.1) "what is hunted;" record; recreant; tachycardia.

It is the hypothetical source of/evidence for its existence is provided by: Greek kardia, Latin cor, Armenian sirt, Old Irish cride, Welsh craidd, Hittite kir, Lithuanian širdis, Russian serdce, Old English heorte, German Herz, Gothic hairto, "heart;" Breton kreiz "middle;" Old Church Slavonic sreda "middle."