pedal-note
noun
ped·al-note ˈpe-dᵊl-ˌnōt 
1
: pedal point
2
: one of the lowest tones that can be sounded on a brass instrument being an octave below the normal usable range and representing the fundamental of the harmonic series
Word History
Etymology
from the playing of the lowest notes on the organ by means of pedals
First Known Use
circa 1828, in the meaning defined at sense 1