Cut a groove into two-master when king's away (4)
I believe the answer is:
etch
'cut' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for etch that I've seen before include "Engrave deeply" , "Cut lines with acid" , "Cut into a block used for printing" , "Cut design onto metal using acid" , "Design on metal or glass using acid" .)