The most common and most likely answer to this crossword clue is the 3 plus 3 plus 5 letter word SEE THE LIGHT
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More clues leading to the result SEE THE LIGHT
- Realise one’s error; rage easily borne
- Fume descending on delicate twig
- Twig to smoulder fine
- Moderate rage first – get it?
- Change to the better storm lamp
- Rise with dawn? Have an epiphany
- Boil with anger before match, maybe, but understand
- Watch the match perhaps to gain a quick insight
- Realise one’s mistake, when switched on?
Buddy explains!

The straight part
We know that "gain a quick insight" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case gain a quick insight = see the light.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.