Lesson to be drawn from a poem or allegory (5)
I believe the answer is:
moral
'lesson' is the definition.
(as in the moral of the story)
'from a poem or allegory' is the wordplay.
'from' indicates a hidden word.
'MORAL' is hidden within 'poem or allegory'.
'to be drawn' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for moral that I've seen before include "Practical lesson to be drawn from an experience" , "Concerned with principles of right and wrong" , "Behaving ethically" , "Upright; message of fable" , "Underlying significance of a story or event" .)