Contrast MP in Cairo cavorting with relative (10)
I believe the answer is:
comparison
'contrast' is the definition.
(thesaurus)
'mp in cairo cavorting with relative' is the wordplay.
'in' is an insertion indicator.
'cavorting' is an anagram indicator.
'with' says to put letters next to each other.
'relative' becomes 'son' (son is a kind of relative**).
'cairo' is an anagram of 'coari'.
'mp' placed into 'coari' is 'compari'.
'compari'+'son'='COMPARISON'
(Other definitions for comparison that I've seen before include "In contrast" , "Analogy; likeness" , "distinction" , "Similarity" , "Assessment of differences" .)