No alfresco party to ruin! (2,2)
I believe the answer is:
do in
This clue might be a double definition.
'no alfresco party' is the first definition.
The definition suggests a verb in its base form which matches the answer.
'ruin' is the second definition.
(thesaurus)
'to' acts as a link.
Can you help me to learn more?
(Other definitions for do in that I've seen before include "Knock off" , "Get rid of" , "Murder" .)