Tunis resort for singles? (5)
I believe the answer is:
units
'singles?' is the definition.
('unit' can be a synonym of 'single')
'tunis resort' is the wordplay.
'resort' indicates an anagram (re-sort the letters).
'tunis' anagrammed gives 'UNITS'.
'for' is the link.
(Other definitions for units that I've seen before include "Individual things or groups" , "Single parts of a whole" , "military teams" , "Single items or standard quantities" , "Figure on the right" .)