Wiktionary
string bass
n. (context musical instrument English) double bass (gloss: lowest-pitched of instruments of violin family)
WordNet
string bass
n. largest and lowest member of the violin family [syn: bass fiddle, bass viol, bull fiddle, double bass, contrabass]
Usage examples of "string bass".
My string bass lay in the middle of the floor, inside a circle of candles.
It was competent and clean -- Hammond Solovox, string bass, and guitar -- and for a while it was the only thing in the whole foul world she could hold on to.
Two members of my 6-piece band, The Soul Merchants, the clarinet and the string bass, were also going to Michigan.