Illustrated Companion to the Latin Dictionary/Operimentum

This article incorporates text from a publication now in the public domain: Rich, Anthony (1849). The illustrated companion to the Latin dictionary, and Greek lexicon. p. vi. OCLC 894670115. https://archive.org/details/illustratedcompa00rich. 

OPERIMEN'TUM. A general name for anything which serves as a cover or covering.