Definition of: arsis

(är′sis) noun plural ·ses (-sēz)
1. In prosody: a The syllable that receives the ictus or stress of voice. b The stress itself. c In the original Greek usage, the raising of the foot in beating time, and hence the metrically unaccented part of the foot: the reverse of modern usage.
2. Music The unaccented part of a bar. [<L <Gk. arsis a lifting, raising <airein raise]