Legal officer briefly touring here in Paris (5)
I believe the answer is:
licit
'legal' is the definition.
(similar in meaning)
'officer briefly touring here in paris' is the wordplay.
'officer briefly' becomes 'lt' (abbreviation for lieutenant; 'briefly' asks for a short form).
'touring' is an insertion indicator (touring can mean going round).
'here in paris' becomes 'ici' ('here' in French).
'lt' going around 'ici' is 'LICIT'.
(Other definitions for licit that I've seen before include "Lawful, permitted" , "Not forbidden, lawful" , "OK?" , "Permitted by law" , "Legal" .)