The most common and most likely answer to this crossword clue is the 5 letter word MORAL
M
O
R
A
L
More clues leading to the result MORAL
- Mark exam in lesson
- Honourable man wasting time
- . Right, second right, then a left
- Man having no time for practical lesson
- Good middle-of-the road album? Not bad
- Right molar operated on
- Man’s timeless lesson
- Decent exam mark given first
- Ethical point initially made by word of mouth
- Lesson master put into speech
Buddy explains!

The straight part
We know that "lesson" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case lesson = moral.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does MORAL mean?
MORAL noun- (of a narrative) The ethical significance or practical lesson.
- (chiefly in the plural) Moral practices or teachings: modes of conduct.
- A morality play.
- A moral certainty.
- An exact counterpart.
- To moralize.
- Of or relating to principles of right and wrong in behaviour, especially for teaching right behaviour.
- Conforming to a standard of right behaviour; sanctioned by or operative on one's conscience or ethical judgment.
- Capable of right and wrong action.
- Probable but not proved.
- Positively affecting the mind, confidence, or will.