(1):

(n.) 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.

(2):

(n.) That elevation of voice now called metrical accentuation, or the rhythmic accent.

(3):

(n.) 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.