The most common and most likely answer to this crossword clue is the 8 letter word ARSONIST
I've seen this crossword clue in The Times
A
R
S
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N
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More clues leading to the result ARSONIST
- One who achieves a burning ambition?
- One getting fires going so trains will move
- Craft transporting child is lighter?
- Fire-raiser nobbled on stairs
- One who's fired prior to his arrest?
- Dear son is tenderly embracing girl holding a torch?
- Possible danger with lighter fluid on stairs
- Does one deserve a lighter sentence?
- Criminal deserving the firing squad?
- Boy is getting into craft that is lighter
Buddy explains!

The straight part
We know that "lighter?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case lighter? = arsonist.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 ARSONIST mean?
ARSONIST noun- One who has committed the act of arson, or illegally setting fire to property.