The most common and most likely answer to this crossword clue is the 8 letter word KEROSENE
K
E
R
O
S
E
N
E
More clues leading to the result KEROSENE
- Paraffin oil’s odd treatment for sore knee
- Keen, perversely, to hoard pink fuel
- Twisted knee, having stood in oil
- Fuel rumours of subterfuge initially swallowed by enthusiastic European
- Field vehicle finally takes red fuel
- Fuel spouted up in field with energy
- One reeks spilling fuel
- Combustible love god in mad keen embrace
- In understanding energy, advanced fuel can be created
- Hydrocarbon project keen on expanding around? Became a rebel
Buddy explains!

The straight part
We know that "Combustible" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case combustible = kerosene.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 KEROSENE mean?
KEROSENE noun- A petroleum-based thin and colorless fuel