Etymology

Noun

1. the burden or bass of a melody

   • 1890: The dim roar of London was like the bourdon note of a distant organ. — Oscar Wilde, The Picture of Dorian Grey
   • 1985: The earth tremors resumed and made a bourdon to the loud psalms that they sang, interspersed with the odd ode of Horace recited by Silas. — Anthony Burgess, Kingdom of the Wicked

1. the drone pipe of a bagpipe
2. the lowest-pitched stop of an organ
3. the lowest-pitched of a peal of bells
4. a bumblebee