Imbrex

Part of speech: noun

Definitions

1. A convex, half-cylindrical roof tile laid over the joints between flat tiles on ancient Roman buildings
2. The rounded clay tile that covered the seams between the flat roofing tiles of classical Roman construction
3. A curved terracotta roofing piece used by the ancient Romans to cover the gaps between the flat tiles beneath it

Etymology: Imbrex is a learned borrowing from Latin, where it named a curved roof tile, the kind laid with its edges overlapping the flat tiles beneath. The Latin word was built from "imber", meaning rain or a rainstorm, with the suffix "-ex". The name points to the job the tile did: channelling rainwater off the roof, which is why the Romans called it after the downpour. English took the word directly from Latin rather than through French, so it has stayed a specialist term for Roman-style roof tiles, used by archaeologists and classicists describing ancient buildings. Its Latin ancestor "imber" is also the root of "imbrue" and "imbrication", the latter describing the overlapping arrangement of scales or tiles.