Alien cheat in ancient African land? (5)
I believe the answer is:
egypt
'ancient african land?' is the definition.
(African country famous since antiquity)
'alien cheat in' is the wordplay.
'alien' becomes 'et' (extra terrestrial).
'cheat' becomes 'gyp' (gyp is a kind of cheat).
'in' is an insertion indicator.
'et' placed around 'gyp' is 'EGYPT'.
(Other definitions for egypt that I've seen before include "North African country" , "Moses' birthplace" , "Cleopatra's country" , "Ancient nation on the Nile" , "Cleopatra its queen" .)