City company has an atmosphere (5)
I believe the answer is:
cairo
'city' is the definition.
(Cairo is an example)
'company has an atmosphere' is the wordplay.
'company' becomes 'co' (abbreviation).
'has' indicates putting letters inside.
'an atmosphere' becomes 'air' (synonyms).
'co' placed around 'air' is 'CAIRO'.
(Other definitions for cairo that I've seen before include "Egyptian capital" , "Capital of Egypt" , "North African capital" , "Al Qahira" , "City near the Nile delta" .)