Renegotiated the loan? This makes you merry (7)
I believe the answer is:
ethanol
'renegotiated the loan? this makes you merry' is the definition.
The definition suggests a singular noun which matches the answer.
'renegotiated the loan? this makes' is the wordplay.
'renegotiated' indicates anagramming the letters.
'this makes' is an anagram indicator.
'the' with letters rearranged gives 'eth'.
'loan' anagrammed gives 'anol'.
'eth'+'anol'='ETHANOL'
Can you help me to learn more?
(Other definitions for ethanol that I've seen before include "spirit" , "volatile flammable substance" , "Alcohol in wine, beer" , "constituent for a dram?" , "Kind of alcohol - not hale (anag)" .)