Went over most significant parts, catching general drift (4)
I believe the answer is:
gist
'general drift' is the definition.
'gist' can be an answer for 'drift' (I've seen this in another clue). I am not certain of the 'general' bit.
'went over most significant parts' is the wordplay.
'went over' is a reversal indicator (I've seen 'gone over' mean this).
'parts' indicates the answer is hidden within the clue (part of the clue provides the answer).
'tsig' can be found hidden inside 'most significant'.
'tsig' written backwards gives 'GIST'.
'catching' is the link.
Can you help me to learn more?
(Other definitions for gist that I've seen before include "The essential point of something" , "General meaning or main point" , "Central meaning or theme" , "Main idea, kernel of matter" , "Substance of an argument" .)