Work about empty environment — lines in e.g. Betjeman's Slough (6)
I believe the answer is:
poetry
'e g betjeman's slough' is the definition.
I can't judge whether this defines the answer.
'work about empty environment lines' is the wordplay.
'work' becomes 'op' (operation, work done in an operating theatre).
'about' says the letters should be written backwards.
'empty' becomes 'E' (abbreviation e.g. on guages).
'environment lines' becomes 'try' (I can't justify this - if you can you should give a lot more credence to this answer).
'op' back-to-front is 'po'.
'po'+'e'+'try'='POETRY'
'in' is the link.
Can you help me to learn more?
(Other definitions for poetry that I've seen before include "Literary art" , "Literature in metrical form" , "Work by Keats or Shelley, say" , "Verse" , "'Best words in best order' (Coleridge)" .)