Dab hand to hold together an ill-assorted coalition (8)
I believe the answer is:
alliance
'ill-assorted coalition' is the definition.
'alliance' can be an answer for 'coalition' (synonyms). I am not certain of the 'ill-assorted' bit.
'dab hand to hold together an' is the wordplay.
'dab hand' becomes 'ace' (I've seen this in another clue).
'to hold' indicates putting letters inside.
'together' becomes 'lli' (I can't explain this - if you can you should believe this answer much more).
'lli'+'an'='llian'
'ace' placed around 'llian' is 'ALLIANCE'.
Can you help me to learn more?
(Other definitions for alliance that I've seen before include "Kind of partnership with canaille" , "Marriage - union" , "League - treaty" , "Combination by treaty" , "Group acting together for common cause" .)