pneumatocyst

noun

pneu·​ma·​to·​cyst ˈn(y)ü-mə-tō-ˌsist 

n(y)u̇-ˈma-tə-

1

: the air bladder of certain algae and aquatic plants

… many seaweeds have floats called pneumatocysts, filled with oxygen or carbon dioxide.

—Michael Le Page

2

: a benign, usually asymptomatic, gas-filled lesion found in bone especially of the ilium, sacrum, or spinal vertebra

Word History

Etymology

pneumato- + -cyst

First Known Use

1859, in the meaning defined at sense 1

Medical Definition

pneumatocyst

noun

pneu·​ma·​to·​cyst ˈn(y)ü-mət-ō-ˌsist 

n(y)u̇-ˈmat-ə-

: a benign, usually asymptomatic, gas-filled lesion found in bone especially of the ilium, sacrum, or spinal vertebra