Watch me infiltrating bank that is extremely conservative (9)
I believe the answer is:
timepiece
'watch' is the definition.
(I've seen this before)
'me infiltrating bank that is extremely conservative' is the wordplay.
'infiltrating' becomes 'tip' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'bank' is an insertion indicator (outside letters create limits or banks).
'that is' becomes 'ie' (abbreviation for id est, 'that is' in Latin).
'extremely' means to remove the middle letters (only the extremes of the word are used).
'conservative' with its centre taken out is 'ce'.
'me' inserted into 'tip' is 'timep'.
'timep'+'ie'+'ce'='TIMEPIECE'
Can you help me to learn more?
(Other definitions for timepiece that I've seen before include "hunter, perhaps" , "alarm, perhaps" , "that sounds the alarm?" , "Maybe watch" , "Watch, say" .)