Rabas are fried or battered squid rings usually served with lemon slices; elsewhere in Spain the dish is called calamares fritos or calamares a la romana.
Spanish Wikipedia notes that fried squid is known in Spain as calamares fritos, calamares a la romana, rabas or calamares a la andaluza, served as a tapa with a slice of lemon or sometimes in a bocadillo de calamares. Wikipedia's Bilbao entry lists rabas among the city's bar snacks. Baster, in the Casco Viejo, pairs its national vermouths and craft beers with a portion of gildas or rabas.
