Wiktionary
stand-up bass
n. (context musical instrument English) double bass (gloss: lowest-pitched of instruments of violin family)
Usage examples of "stand-up bass".
They were in the midst of discussing options, with Riker suggesting that he could teach her to play stand-up bass--she'd never heard of a stand-up bass --when Dokachin sent a message from the surface informing them that he had found the collaborator.