dipnoi Meaning, Definition & Usage

  1. noun bony fishes of the southern hemisphere that breathe by a modified air bladder as well as gills; sometimes classified as an order of Crossopterygii
    subclass Dipnoi.

WordNet

Dip"no*i noun plural
Etymology
NL., fr. Gr. with two breathing apertures; = twice + breath.
Definitions
  1. (Zoöl.) A group of ganoid fishes, including the living genera Ceratodus and Lepidosiren, which present the closest approximation to the Amphibia. The air bladder acts as a lung, and the nostrils open inside the mouth. See Ceratodus, and Illustration in Appendix.

Webster 1913