involucrum

noun

in·​vo·​lu·​crum ˌin-və-ˈlü-krəm 

plural involucra ˌin-və-ˈlü-krə 

: a surrounding envelope or sheath

Examples of involucrum in a Sentence

Recent Examples on the Web

Its jaws and teeth were similar to those of early whales, but the best evidence was the presence of a thickened knob of bone in its middle ear, called an involucrum. —Ed Yong, Discover Magazine, 7 May 2010

Word History

Etymology

borrowed from New Latin involūcrum, going back to Latin, "wrapper, cover, envelope," from involū-, variant stem of involvere "to move by rolling, roll back on itself, enclose in a covering, wrap up" + -crum, variant of -culum, instrumental suffix (going back to Indo-European *-tlom) before a preceding l — more at involve

First Known Use

1657, in the meaning defined above

Medical Definition

involucrum

noun

in·​vo·​lu·​crum ˌin-və-ˈlü-krəm 

plural involucra -krə 

: a formation of new bone about a sequestrum (as in osteomyelitis)