arabesque n.

1786, "Moorish or Arabic ornamental design," from French arabesque (16c.), from Italian arabesco, from Arabo "Arab" (see Arab), with reference to Moorish architecture. In reference to an ornamented theme or passage in piano music it is attested by 1853, originally the title given in 1839 by Robert Schumann to one of his piano pieces ("Arabeske in C major"). As a ballet pose, attested by 1830.

The name arabesque applied to the flowing ornament of Moorish invention is exactly suited to express those graceful lines which are their counterpart in the art of dancing. ["A Manual of the Theory and Practice of Classical Theatrical Dancing," 1922]