Introductory textbook, gloss over it perhaps? (6)
I believe the answer is:
primer
'introductory textbook' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for primer that I've seen before include "First coat - book" , "Basic teaching book" , "Introductory textbook or first coat of paint" , "School textbook" , "Solitary" .)