The king of Spain’s trumpeter; a braying ass. His trumpeter is dead, he is therefore forced to sound his own trumpet. He would make an excellent trumpeter, for he has a strong breath; said of one having a foetid breath.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Trumpet * TrumpsNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes