Hard to avoid Escort or a person on horse, say (4)
I believe the answer is:
user
'a person on horse say' is the definition.
I can't tell whether this defines the answer.
'hard to avoid escort' is the wordplay.
'hard' becomes 'h' (abbreviation used in pencil classifications).
'to avoid' is a deletion indicator.
'escort' becomes 'usher' (usher is a kind of escort).
'usher' with 'h' taken out is 'USER'.
'or' acts as a link.
Can you help me to learn more?
(Other definitions for user that I've seen before include "One who works an appliance" , "One who exploits others" , "Ruse (anag.)" , "Someone who exploits another" , "junkie" .)