Medallion Uşak carpet, from an Istanbul tomb. 16th century.

From Enc. Britt.: any floor covering on which the decoration is dominated by a single geometric centrepiece, suchas a star-shaped, circular, quatrefoiled, or octagonal figure. The name, however, is sometimes also given to a carpet on which the decoration consists of several forms of this kind or even of rows ofmedallion figures. [...]In Ottoman Turkish and Egyptian classic carpets, the lobed circle was the most common medallion form, as in more recent Chinese carpets. Ottoman weavers used the quarter-medallion cornerpiece, but the Chinese preferred to balance against the central figure completesmaller roundels near the corners.