Chap flies up over Ibiza, avoiding unknown African state (7)
I believe the answer is:
namibia
'african state' is the definition.
(country in Africa)
'chap flies up over ibiza avoiding unknown' is the wordplay.
'chap' becomes 'man' (I've seen this before).
'flies up' is a reversal indicator.
'over' is a charade indicator (letters next to each other).
'avoiding' indicates named letters should be taken away.
'unknown' becomes 'z' (algebra).
'man' written backwards gives 'nam'.
'ibiza' with 'z' removed is 'ibia'.
'nam'+'ibia'='NAMIBIA'
(Other definitions for namibia that I've seen before include "African republic" , "Southern African country" , "South African country" , "South West Africa" , "Southwest African country" .)