Funny secret about Haiti's capital city (7)
I believe the answer is:
chester
'city' is the definition.
(Chester is an example)
'funny secret about haiti's capital' is the wordplay.
'funny' is an anagram indicator.
'about' means one lot of letters goes inside another.
'capital' suggests taking the first letters.
The first letter of 'haitis' is 'h'.
'secret' anagrammed gives 'cester'.
'cester' going around 'h' is 'CHESTER'.
(Other definitions for chester that I've seen before include "Tetchy cries (anag)" , "diocese" , "Cathedral city" , "See 8" , "County town south of Liverpool" .)