What is the meaning of the word "quassia"?

Definitions:

  1. a bitter compound used as an insecticide and tonic and vermifuge copy to clipboard noun
    • We rubbed quassia on our exposed skin to ward off insects. copy to clipboard
  2. handsome South American shrub or small tree having bright scarlet flowers and yielding a valuable fine-grained yellowish wood copy to clipboard noun
    • Quassia is a fine looking plant. copy to clipboard