Praising fantastic gig in Seoul (10)
I believe the answer is:
eulogising
'praising' is the definition.
(eulogising is a kind of praising)
'fantastic gig in seoul' is the wordplay.
'fantastic' indicates anagramming the letters (a fantastic or improbable ordering of the letters).
'gig'+'in'+'seoul'='giginseoul'
'giginseoul' anagrammed gives 'EULOGISING'.
(Other definitions for eulogising that I've seen before include "Extolling" , "Praising" .)