The story
From Italian, meaning "marine trumpet". * The tromba may originate in a comparison to the valveless trumpet of the Middle Ages, which produced harmonic overtones like the tromba marina, or as a reference to the unique trumpet-like rasping sound created by the intentionally loose bridge of the instrument vibrating against its face. The marina may refer to the Virgin Mary, perhaps because the instrument was played by nuns in convents.
Etymology from Wiktionary, CC BY-SA 4.0.