After all, maybe a nice merger (8)
I believe the answer is:
alliance
'merger' is the definition.
(thesaurus)
'after all maybe a nice' is the wordplay.
'after' says to put letters next to each other.
'maybe' indicates an anagram.
'a'+'nice'='anice'
'anice' is an anagram of 'iance'.
'all' put next to 'iance' is 'ALLIANCE'.
(Other definitions for alliance that I've seen before include "Group acting together for common cause" , "match?" , "Formal agreement" , "Union for mutual benefit" , "Kind of partnership with canaille" .)