Elytrum

1. n. One of the shieldlike dorsal scales of certain annelids. See Chaetopoda.
2. n. One of the anterior pair of wings in the Coleoptera and some other insects, when they are thick and serve only as a protection for the posterior pair.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.