Origin of half-line
Examples from the Web for half-line
Whether the half-line be first or second, it is usually of the A type without anacrusis.
Whether the number of accents in the second half-line was ever diminished to two, may be doubted.Chaucer's Works, Volume 3 (of 7)|Geoffrey Chaucer
Type E inverts the rhythm of D, as in the half-line "gylp-wordum spræc."English Verse|Raymond MacDonald Alden, Ph.D.
Every normal line of Old English poetry has four primary accents, two in the first half-line and two in the second half-line.
It is also the only alliterating syllable in the second half-line.