Creature roaming randomly round capital in Sudan (8)
I believe the answer is:
organism
'creature' is the definition.
(thesaurus)
'roaming randomly round capital in sudan' is the wordplay.
'randomly' is an anagram indicator (I've seen 'roaming randomly' mean this).
'round' is an insertion indicator.
'capital in' suggests taking the first letters.
The initial letter of 'sudan' is 's'.
'roaming' anagrammed gives 'organim'.
'organim' placed around 's' is 'ORGANISM'.
(Other definitions for organism that I've seen before include "Living animal or vegetable" , "Living animal or plant" , "Living thing -- man's giro (anag)" , "Something alive" , "Individual life form" .)