The thingabout is a specially invented form, starting with some phrase like, the thing about... or the bit about... or the problem with. The following gives the idea:

The thingabout’s for everyone
and this is how the form is spun:
the subject given in line one –
it can be anything beneath the sun –
is followed by, and here’s the fun,
at least a six line rhyming run.
like rapid firing of a gun,
with hopefully some wit or pun.
Another rhyme in manner terse,
concludes this little comic verse.