Oil supplier worked in Leeds (7)
I believe the answer is:
linseed
'oil supplier' is the definition.
'linseed' can be an answer for 'oil' (I've seen this before). I'm not sure about the 'supplier' bit.
'worked in leeds' is the wordplay.
'worked' indicates anagramming the letters.
'in'+'leeds'='inleeds'
'inleeds' is an anagram of 'LINSEED'.
Can you help me to learn more?
(Other definitions for linseed that I've seen before include "Source of plant oil" , "Oil produced from flax" , "Flax product, a source of oil" , "Flax plant product providing oil" , "Oil applied to cricket bats" .)