Carefully examine extremely specific action (4)
I believe the answer is:
scan
'carefully examine' is the definition.
'scan' can be an answer for 'examine' (scanning is a kind of examining). I'm unsure of the 'carefully' bit.
'extremely specific action' is the wordplay.
'extremely' means to remove the middle letters (only the extremes of the word are used).
'action' becomes 'an' (I am not sure about this - if you are sure you should believe this answer much more).
'specific' with its centre removed is 'sc'.
'sc'+'an'='SCAN'
Can you help me to learn more?
(Other definitions for scan that I've seen before include "Run over" , "Examine data" , "Survey - fit in metrically" , "Examine hastily" , "Look at quickly" .)