Irish lass embraces leader, one providing relief work (8)
I believe the answer is:
embosser
'one providing relief work' is the definition.
The definition suggests a singular noun which matches the answer.
'irish lass embraces leader' is the wordplay.
'irish lass' becomes 'emer' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'embraces' is an insertion indicator.
'leader' becomes 'boss' (boss is a kind of leader).
'emer' placed around 'boss' is 'EMBOSSER'.
Can you help me to learn more?
(Other definitions for embosser that I've seen before include "Relief worker" , "Surface designer" , "who makes an outstanding contribution to art?" .)