Meaning

noun a large stringed instrument; seated player holds it upright while playing

originClipping of violoncello, the original name, from Italian violoncello (“little violone”), from violone (“an early form of the double bass”) + -cello (“-elle”, forming diminutives), violone (“big viola”) itself being derived from viola + -one (“-oon”, forming augmentatives).

Etymology from Wiktionary, CC BY-SA 3.0