Dictionary.net

• Cossis. A sort of white, short, thick worm or larve, found in trees, logs of wood, &c., and used by the Romans as great article of gourmandise. They were, also, applied to ulcers. - Pliny. The term has, likewise, been given to small vermiform pimples on the face- acne- which arise from inflammation of the sebaceous follicles.

1846 - Medical lexicon: a dictionary of medical science
By Robley Dunglison