The Collaborative International Dictionary of English v.0.48:
Pneumonitis \Pneu`mo*ni"tis\, n. [NL. See Pneumo-, and -itis.] (Med.) Inflammation of the lungs; pneumonia. [1913 Webster]WordNet (r) 3.0 (2006):
pneumonitis n 1: inflammation of the lungs; caused by a virus or an allergic reaction