Prompt student included one such as this (4)
I believe the answer is:
clue
'this' is the definition.
(the clue referring to itself!)
'prompt student included' is the wordplay.
'prompt' becomes 'cue' (cue can mean a prompt or signal).
'student' becomes 'L' (as in L-plates for learner drivers).
'included' indicates putting letters inside.
'cue' going around 'l' is 'CLUE'.
'one such as' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for clue that I've seen before include "It's here top be solved" , "Crossword help" , "Hint, tip" , "Hint; piece of evidence" , "Aid to puzzlers" .)