[French crétin, from French dialectal, deformed and mentally retarded person found in certain Alpine valleys, from Vulgar Latin *christiānus, Christian, human being, poor fellow, from Latin Chrīstiānus, Christian; see Christian.] cre'tin·oid' (-oid') adj., cre'tin·ous (-əs) adj.
1779, from Fr. Alpine dialect crestin, "a dwarfed and deformed idiot," from V.L. *christianus "a Christian," a generic term for "anyone," but often with a sense of "poor fellow."