Japanese verse form of three short lines (5)
I believe the answer is:
haiku
'japanese verse form of three short lines' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for haiku that I've seen before include "17-syllable Japanese verse form" , "Short Japanese poem" , "Eastern poetry" , "Japanese verse form of three short lines" , "Jap 17 syllable poem" .)