Egyptian peninsula or some Egyptian islands seen from the south (5)
I believe the answer is:
sinai
'egyptian peninsula' is the definition.
(I've seen this before)
'some egyptian islands seen from the south' is the wordplay.
'some' says the answer is hidden in the clue (some parts of the word are used).
'from the south' says the letters should be written in reverse (in a down clue, letters go up).
'ianis' can be found hidden inside 'egyptian islands seen'.
'ianis' written backwards gives 'SINAI'.
'or' acts as a link.
(Other definitions for sinai that I've seen before include "Egyptian desert" , "Ten Commandments mountain" , "Mount where Moses received God's law" , "Mountainous Egyptian peninsula" , "Part of 10 [EGYPT]" .)