portobello meaning
Define Portobello mushroom. Portobello mushroom synonyms, Portobello mushroom pronunciation, Portobello mushroom translation, English dictionary definition of Portobello mushroom. or porÂ·taÂ·belÂ·la or porÂ·toÂ·belÂ·la n. pl. porÂ·toÂ·belÂ·los or porÂ·taÂ·belÂ·las A mature, dark-brown form of the common cultivated mushroom . n , pl -los a large...