Form that saves time for the writer (12)
I believe the answer is:
abbreviation
'form' is the definition.
(abbreviation is a kind of form)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for abbreviation that I've seen before include "Shortening - above Britain (anag)" , "eg, may be one" , "A short word" , "RAF, for example" , "Shortened form of a word or phrase" .)