book lung

noun

1. the respiratory organ of a spider, scorpion, or other arachnid, composed of thin, membranous structures arranged like the leaves of a book.

book lung

/ bk /

1. 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.

Word History and Origins

Origin of book lung¹

First recorded in 1895–1900