"bassa latinita' " is the Italian equivalent of "vulgar latin." Vulgar is NOT the Latin you might have learned at school. It is rather the Latin spoken by the common man of the time. It is from VULGAR Latin that the Romance languages (French, Spanish, Italian Portuguese, Romanian, Catalan, etc.) are derived. "Vulgar" doesnot mean obscene, but refers to the Latin spoken by the "VULGUS" (that is, the common man).