Frantically, peer needs potty (4,3)
I believe the answer is:
like mad
'frantically' is the definition.
(thesaurus)
'peer needs potty' is the wordplay.
'peer' becomes 'like' (both can mean an equal).
'needs' says to put letters next to each other.
'potty' becomes 'mad' (potty can informally mean mad).
'like'+'mad'='LIKE MAD'
(Other definitions for like mad that I've seen before include "Energetically" , "With furious enthusiasm" , "wildly" , "Furiously" , "Very quickly" .)