A strict form of Japanese poetry consisting of 3 lines.

Format:
First Line 5 Syllables
Second Line 7 Syllables
Third Line 5 Syllables

Haiku are strictly about nature. All of the definitions posted here are incorrect, those are senryu, which are haiku that do not deal with nature.

Haikus have three lines.
The first has five syllables,
Then seven, then five.

Proper haikus are about nature, especially the seasons; the structure tends to be more important than the words.

A Japanese form of poetry used by lazy people.

A type of Japanese poetry composed of three unrhyming lines, Most likely used by the Wapanese or otaku when they aren't fighting over which episode of Hamtaro was the best.

A short poem where as the first line has 5 syllables, the second has 7 and the last has 5. This form of poetry does not have to, and rarely does make sense.

A form of poetry that has a certain format. The format of the poem is, the first line 5 syllables, the second 7 syllables and the third 5 syllables