Definition of haiku:
(n) :
a Japanese poem of a specific form, consisting of three lines, the first and last consisting of five Japanese letters, and the second consisting of seven Japanese letters, usually with an emphasis on the season or a naturalistic theme; a three-line poem in any language, with five syllables in the first and last lines and seven syllables in the second, usually with an emphasis on the season or a naturalistic theme
"haiku, a poem"