Sage from Dublin I dropped completely (5)
I believe the answer is:
rishi
'sage' is the definition.
(term for a Hindu sage)
'from dublin i dropped completely' is the wordplay.
'from dublin' becomes 'irish' (Dublin is in Ireland).
'dropped' suggests deleting specific letters.
'completely' becomes 'i' (I can't justify this - if you can you should give a lot more credence to this answer).
'irish' with 'i' taken out is 'rish'.
'rish'+'i'='RISHI'
(Other definitions for rishi that I've seen before include "Hindu sage or saint" , "Guru" , "Spiritual leader" , "holy man" , "Revered man" .)