Why is the ninth month called September?
"pertaining to the lungs," 1670s, from Latin pneumonicus, from Greek pneumonikos "of the lungs," from pneumon (see pneumonia).
pneumonic pneu·mon·ic (nu-mŏn'ĭk, nyu-)adj.
Relating to, affected by, or similar to pneumonia.
Of, affecting, or relating to the lungs; pulmonary.