Okay, in Spanish the word for trumpet and trumpeter is trompeta.
Trompeta also means "useless individual" and "drunkard."

I actually find this quite amusing.

Nice observation, I think I see the connection. Brass player specially trumpets have tendancy to get drunk a lot so much that the only time there sober is when there actually performing. (even this hasnt stopped some people i know) I think its a bit sad that so many brass players are like this because it probably destroys so many good players.

Sorry,
in no way "trompeta" does mean any of the two
definitions you gave, nor any reference to.
You only could say "esta` trompa" (nothing to do with any musical instrument) to a drunkard.
Regards.

I have two different dictionaries to back myself up.