Time to go to busy places to catch European criminals (7)
I believe the answer is:
thieves
'criminals' is the definition.
(thief is a kind of criminal)
'time to go to busy places to catch european' is the wordplay.
'time' becomes 't'.
'to go to' says to put letters next to each other.
'busy places' becomes 'hives'.
'to catch' means one lot of letters goes inside another.
'european' becomes 'e' (abbreviation e.g. EU).
'hives' placed around 'e' is 'hieves'.
't'+'hieves'='THIEVES'
(Other definitions for thieves that I've seen before include "they whip things" , "Light-fingered people" , "They pinch" , "Robbers" , "Unit of length" .)