pantile

noun

1. a roofing tile straight in its length but curved in its width to overlap the next tile.
2. a tapered, semicylindrical roofing tile laid either convex side up to overlap flanking similar tiles laid concave side up or vice versa.

noun

1. a roofing tile, with an S-shaped cross section, laid so that the downward curve of one tile overlaps the upward curve of the adjoining tile
2. a tapering roofing tile with a semicircular cross section, laid alternately so that the convex side of one tile overlaps the concave side of adjoining tiles