Fish around one island up in the republic (7)
I believe the answer is:
tunisia
'the republic' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'fish around one island up' is the wordplay.
'fish' becomes 'tuna' (tuna is a type of fish).
'around' means one lot of letters goes inside another.
'one' becomes 'i' (Roman numeral).
'island' becomes 'is' (geographical abbreviation).
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'is' backwards is 'si'.
'i'+'si'='isi'
'tuna' going around 'isi' is 'TUNISIA'.
'in' is the link.
Can you help me to learn more?
(Other definitions for tunisia that I've seen before include "Republic in northwestern Africa" , "Country between Algeria/Libya" , "country-style" , "African republic on the Mediterranean coast" , "N African country in which ancient Carthage lies" .)