In western Galician, from Old Galician-Portuguese *sẽara; in eastern Galician from senra. Attested in local Medieval Latin documents since the 9th century as senara, from Paleo-Hispanic *senara, probably a compound of Celtic origin, from Proto-Celtic *senara (“piece of land cultivated on the side”), from *sen- (“separation”) (<< Proto-Indo-European *swé (“self”)) + *aryeti (“to plow”). Cognate with Portuguese senra, seara and Spanish serna.