Cleric has played lyre in merry-making (7)
I believe the answer is:
revelry
'merry-making' is the definition.
(I've seen this before)
'cleric has played lyre' is the wordplay.
'cleric' becomes 'rev' (abbreviation for Reverend).
'has' means one lot of letters go next to another.
'played' indicates an anagram.
'lyre' with letters rearranged gives 'elry'.
'rev'+'elry'='REVELRY'
'in' acts as a link.
(Other definitions for revelry that I've seen before include "Noisy celebration" , "Lively celebrations" , "Feasting, noisy festivities" , "Riotous feasting" , "Jolly parties" .)