Oil producers lie and cut pay anyhow (9)
I believe the answer is:
eucalypti
'oil producers' is the definition.
(I've seen this before)
'lie and cut pay anyhow' is the wordplay.
'and' means one lot of letters go next to another.
'anyhow' indicates an anagram.
'lie'+'cut'+'pay'='liecutpay'
'liecutpay' with letters rearranged gives 'EUCALYPTI'.
(Other definitions for eucalypti that I've seen before include "Oil sources" , "Antipodean natives" , "Gums" , "Oil producers" , "Australian trees" .)