as far as i know it's a representational word for a season. there's a big big list somewhere for Japanese kigo but in general it can something associated with a particular season, ie; frogsborn, lamb cuckoo high rivers.
it has no bearing apart from being a seasonal word. english is english and japanese is japanese, it a bit like comparing the apple to the orange syndrome. it can't be done. the rules are more or less a translation a bit of jiggary pokery and a hammer to squeeze it into english we have some yosa no buson who wrote a fair few haiku (japanese style) here
and some Matsuo Basho haiku here
it has no bearing apart from being a seasonal word. english is english and japanese is japanese, it a bit like comparing the apple to the orange syndrome. it can't be done. the rules are more or less a translation a bit of jiggary pokery and a hammer to squeeze it into english we have some yosa no buson who wrote a fair few haiku (japanese style) here
and some Matsuo Basho haiku here