hemistich

An approximate half-line of verse, separated from another by a caesura, often for dramatic effect.

[…] I would first agree with [Earl] Wasserman that the last line ["[shapes] Which walk upon the sea, and chaunt melodiously"] alludes to Jesus walking on water, the point of the allusion being the kerygmatic expression of a form of transcendence, which is more or less specified by the way the other hemistych of this remarkably balanced thirteener – "and chaunt melodiously" – recalls how it is on the breath of enamored air and song that all the vigorously launched members and voices of this scene are sustaining their courses.

An unfinished line of verse.