Sinister 2001 character is well short (3)
I believe the answer is:
hal
'sinister 2001' is the definition.
I can't tell whether this defines the answer.
'character is well short' is the wordplay.
'character' becomes 'e'.
'is well' becomes 'hale' (I've seen this in another clue).
'short' indicates named letters should be taken away (to be short of something is to lack it).
'hale' with 'e' taken out is 'HAL'.
Can you help me to learn more?
(Other definitions for hal that I've seen before include "Shakespeare's Prince_with Falstaff" , "Shakespeare's prince" , "Falstaff's Prince; 2001 computer" , "Man" , "Odyssean character" .)