Permit sailor to work on Irish ship if satisfactory (8)
I believe the answer is:
passable
'satisfactory' is the definition.
(similar in meaning)
'permit sailor to work on irish ship' is the wordplay.
'permit' becomes 'pass' (pass is a kind of permit).
'sailor' becomes 'ab' (abbreviation for able seaman).
'to work on irish ship' becomes 'le' (I can't justify this - if you can you should give a lot more credence to this answer).
'pass'+'ab'+'le'='PASSABLE'
'if' is the link.
Can you help me to learn more?
(Other definitions for passable that I've seen before include "Fair" , "Fairly good but not outstanding" , "okay?" , "not hogging the road" , "Barely adequate" .)