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.
HAIKU:
Whispering softly
Willow trees in the winter
Sway in the cold wind.
SENRYU:
I have a big cock
It is much bigger than yours
Yours is just too small
Whispering softly
Willow trees in the winter
Sway in the cold wind.
SENRYU:
I have a big cock
It is much bigger than yours
Yours is just too small
by Alexis Rose February 02, 2007
by Alexis Rose December 17, 2006