Picnic area ruined with exceptional rain falling? It can make you sick (6)
I believe the answer is:
ipecac
'it can make you sick' is the definition.
The definition suggests a singular noun which matches the answer.
'picnic area ruined with exceptional rain falling?' is the wordplay.
I cannot quite understand how this works, but
'area' could be 'ec' and 'ec' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for ipecac that I've seen before include "That could make you sick!" , "that could make you puke" , "Purgative" , "Drug" .)