Monkey we might catch in this American city (5)
I believe the answer is:
tampa
'american city' is the definition.
(city in Florida)
'monkey we might catch in this' is the wordplay.
'monkey' becomes 'tamper' (to monkey with is to tamper with).
'we might catch in this' indicates a 'sounds like' (homophone) clue (catch can mean to hear).
'tamper' sounds like 'TAMPA'.
(Other definitions for tampa that I've seen before include "City in Florida" , "US city" , "Resort in W. Florida" , "US resort" , "American city" .)