A bassoon is a musical instrument with a low, rich tone. A bassoon is like a deep, bass version of an oboe.
In the category of woodwind instruments, which have reeds that rest on the musician's lips as she plays, the bassoon is the deepest-sounding. You will probably hear at least one bassoon if you attend a band or orchestral concert. The word bassoon comes from the 17th century French basson, sharing a Latin root with bass — bassus, or "low."