Crossword Genius

Chief renderer’s first undercoat (6)

Ross

I believe the answer is:

primer

'undercoat' is the definition.
(preliminary coat of paint)

'chief renderer's first' is the wordplay.
'chief' becomes 'prime' (I've seen this before).
'first' suggests taking the first letters.
The initial letter of 'renderer' is 'r'.
'prime'+'r'='PRIMER'

(Other definitions for primer that I've seen before include "Introductory textbook or first coat of paint" , "Sealant coat" , "Preparatory coat of paint" , "Basic book; undercoat" , "small book of prayer" .)

I've seen this clue in The Mirror.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.