Rubbish poetry aches endlessly - that's the long and the short of it (7)
I believe the answer is:
trochee
'rubbish poetry aches endlessly that's the long' is the definition.
I can't tell whether this defines the answer.
'the short of it' is the wordplay.
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'short of' becomes 'roche' (I am not sure about this - if you are sure you should believe this answer much more).
'it' becomes 'e' ('e' can mean 'electronic' which is similar to 'IT').
't'+'roche'+'e'='TROCHEE'
'and' is the link.
Can you help me to learn more?
(Other definitions for trochee that I've seen before include "service, for example" , "Long-short foot in poetry" , "Metric foot; to cheer (anag.)" , "To cheer about this metrical unit" , "Using foot" .)