Terminator, perhaps, with immodesty firstly in bar (7)
I believe the answer is:
android
'terminator perhaps' is the definition.
(the film character the Terminator is an example)
'with immodesty firstly in bar' is the wordplay.
'with' becomes 'and'.
'firstly' suggests taking the first letters.
'in' means one lot of letters goes inside another.
'bar' becomes 'rod' (I've seen this before).
The initial letter of 'immodesty' is 'i'.
'i' put within 'rod' is 'roid'.
'and'+'roid'='ANDROID'
(Other definitions for android that I've seen before include "Automaton resembling a human" , "artificial being" , "Human-type robot" , "Humanoid robot" , "Automaton that resembles a human being" .)