Defn: A division of holothurians having an internal gill, or respiratory tree.
PNEUMOSKELETON
Pneu`mo*skel"e*ton, n. Etym: [Pneumo- + skeleton.] (Zoöl.)
Defn: A chitinous structure which supports the gill in some invertebrates.
PNEUMOTHERAPY
Pneu`mo*ther"a*py, n. Etym: [Gr. therapy.] (Med.)
Defn: The treatment of disease by inhalations of compressed or rarefied air.
PNEUMOTHORAX
Pneu`mo*tho"rax, n. Etym: [Gr. thorax.] (Med.)
Defn: A condition in which air or other gas is present in the cavity of the chest; — called also pneumatothorax.
PNIGALION
Pni*ga"li*on, n. Etym: [NL., fr. Gr. (Med.)
Defn: Nightmare.
PNYX
Pnyx, n. Etym: [NL., fr. Gr. (Gr. Antiq.)