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Webster 1913 Edition

Adj.

[L.

pulmo

a lung +

gradi

to walk.]

(Zool.)

Swimming by the expansion and contraction, or lunglike movement, of the body, or of the disk, as do the medusæ.

pulmograde ‎(not comparable)

(zoology) Swimming by means of expansion and contraction.
The medusae are pulmograde.