Arsis
Pronunciation : Ar"sis
Part of Speech : n.
Etymology : [L. arsis, Gr. lifting of the hand in beating time, and hence the unaccented part of the rhythm.]
Definition : 1. (Pros.) (a) That part of a foot where the ictus is put, or which is distinguished from the rest (known as the thesis) of the foot by a greater stress of voice. Hermann. (b) That elevation of voice now called metrical accentuation, or the rhythmic accent.
Note: It is uncertain whether the arsis originally consisted in a higher musical tone, greater volume, or longer duration of sound, or in all combined.
2. (Mus.)
Defn: The elevation of the hand, or that part of the bar at which it is raised, in beating time; the weak or unaccented part of the bar; - - opposed to thesis. Moore.
Source : Webster's Unabridged Dictionary, 1913