Initially exposing omission, turning over part of text (4)
I believe the answer is:
page
'part of text' is the definition.
'page' can be an answer for 'text' (thesaurus). I am not certain of the 'part of' bit.
'initially exposing omission turning over' is the wordplay.
'initially' says to take the initial letters.
'omission turning' becomes 'gap' (I am not sure about this - if you are sure you should believe this answer much more).
'over' is a reversal indicator.
The initial letter of 'exposing' is 'e'.
'e'+'gap'='egap'
'egap' backwards is 'PAGE'.
Can you help me to learn more?
(Other definitions for page that I've seen before include "lad wanted to run errands" , "Piece of paper for a young attendant" , "Boy at match" , "Side" , "Youth acting as a knight's attendant" .)