Make a list of awful, semiliterate letters, later abandoned (7)
I believe the answer is:
itemise
'make a list' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for itemise that I've seen before include "List one by one (S, not Z)" , "Formulate a list" , "List out singly" , "Using spell out" , "List in detail" .)