From Old Galician-Portuguese garça (13th century, Cantigas de Santa Maria), from a substrate language, probably Hispano-Celtic or Celtiberian [Term?], from Proto-Celtic *korkiyos; akin to Welsh crychydd, Breton kerc'heiz.
Cognate with Spanish garza, Mirandese garça, Asturian garza, Portuguese garça, and (possibly) Catalan garsa.