Fellow celeb one about in state (5,4)
I believe the answer is:
costa rica
'state' is the definition.
(Costa Rica is an example)
'fellow celeb one about' is the wordplay.
I cannot quite see how this works, but
'fellow' could be 'co' (eg a co-worker is a fellow worker) and 'co' is present in the answer.
'celeb' could be 'star' (I've seen this in another clue) and 'star' is located in the answer.
'one' could be 'i' (Roman numeral) and 'i' is located in the answer.
'about' could be 'ca' (abbreviation for 'circa') and 'ca' is located in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
'in' acts as a link.
Can you help me to learn more?
(Other definitions for costa rica that I've seen before include "A Socratic kind of country in S America" , "place in Central America" , "Central American state" , "Central American country, capital San Jose" , "Central American nation" .)