Cipher Joby made to shift alphabetically (4)
I believe the answer is:
zero
'cipher' is the definition.
(I know that cipher can be written as zero)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for zero that I've seen before include "Duck" , "Very bad visibility" , "Less than one" , "The hour to leave" , "value?" .)