In Dublin see diesel oil producer? (7)
I believe the answer is:
Here is my best explanation:
'oil producer?' is the definition.
'in dublin see diesel' is the subsidiary indication.
'in' indicates a hidden word.
'linseed' can be found hidden inside 'dublin see diesel'.
(Other definitions for linseed that I've seen before include "Source of plant oil", "Oil applied to cricket bats", "Treatment for bats", "Oil-producing plant", "Part of flax used as oil", "Product of the flax plant", "Oil produced from flax", "Flax plant product providing oil", "Oil source" and "Enisled (anag.)".)