Illustrated Companion to the Latin Dictionary/Optostrotum
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.
OPTOSTRO'TUM. A flooring made, or paved, with bricks. Not. Tires. p. 164.; from ὀπτος, coctus, and στρωτόν, stratum.