12th century. Inherited from Old Galician-Portuguese manteiga, already attested with this spelling in a Galician Latin document from 1118; from Paleo-Hispanic, perhaps from Proto-Indo-European (cf. Bulgarian, Russian and Ukrainian сметана (smetana), Polish śmietana, Slovak smotana and Slovene smetana). Cognate with Portuguese manteiga, Asturian mantega, Spanish manteca and Catalan mantega.