- (In a spider or other arachnid) each of a pair of respiratory organs composed of many fine leaves. They are situated in the abdomen and have openings on the underside.More example sentences
- Most spiders breathe through tracheae; some, like the wolf spiders, have both book lungs and tracheae.
- Like spiders, they were terrestrial and respired through book lungs, and walked on eight legs.
- Respiration takes place through the body surface, and/or by means of gills, tracheae, or book lungs.
More definitions of book lungDefinition of book lung in:
- The British & World English dictionary