refrigerator n.

1530s, "to cool, make cool," a back-formation from refrigeration, or else from Latin refrigeratus, past participle of refrigerare "make cool or cold." Related: Refrigerated; refrigerating. Earlier words in the sense of "to make cold, to cool" were infrigiden, infrigidate (both early 15c.). Middle English had refroiden "to cool" (anger), mid-15c., from Old French refroider.

shortened and altered form of refrigerator, 1926, an unusual way of word-formation in English; perhaps influenced by Frigidaire (1919), name of a popular early brand of self-contained automatically operated iceless refrigerator (Frigidaire Corporation, Detroit, Michigan, U.S.), a name suggesting Latin frigidarium "a cooling room in a bath." Frigerator as a colloquial shortening is attested by 1886.