The Collaborative International Dictionary of English v.0.48:
Arietta \A`ri*et"ta\, Ariette \Ar`i*ette"\, n. [It. arietta, dim. of aria; F. ariette.] (Mus.) A short aria, or air. "A military ariette." --Sir W. Scott. [1913 Webster]WordNet (r) 3.0 (2006):
arietta n 1: a short aria [syn: arietta, short aria]