the respiratory organ of a spider, scorpion, or other arachnid, composed of thin, membranous structures arranged like the leaves of a book.
Origin of book lung
First recorded in 1895–1900
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
The breathing organ of scorpions, spiders, and some other arachnids. It consists of membranes arranged in several parallel folds like the pages of a book.
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