medianoche

midnight; a small meat pie; a type of sandwich with spherical shaped roles and meats ranging from Sobrasada sausage, York ham or chorizo, containing cheese and even sometimes pieces of a Spanish omelette; a roll used for said sandwich; hot dog bun

“Me voy a dormir a medianoche” — I go to sleep at midnight

From media, feminine of medio (“middle”), and noche (“night”). Compare Portuguese meia-noite, French minuit, Italian mezzanotte.