Why was "tantrum" trending last week?
1852, from French tuba, from Latin tuba (plural tubæ) "straight bronze war trumpet" (as opposed to the crooked bucina), related to tubus (see tube).
The lowest-pitched of the brass instruments. In orchestras, the tuba is usually held across the player's lap. In marching bands, the sousaphone is generally used as a low brass instrument because it was designed to be carried.