The most common and most likely answer to this crossword clue is the 8 letter word IGNITION
I've seen this crossword clue in The Daily Telegraph
I
G
N
I
T
I
O
N
More clues leading to the result IGNITION
- What drivers need to get fired up?
- Some sign it ionised, creating spark
- Fire engine must need this
- Firing international, into gin unfortunately
- Sign it? I only will admit firing
- Key is required for this part of estate, say
- System for firing one caught in observing another one from behind
- It’s key here to activate estate, maybe?
- Firing favourite absent from planned petitioning
- Firing it in going off without finishing
Buddy explains!

The straight part
We know that "firing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case firing = ignition.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 IGNITION mean?
IGNITION noun- The act of igniting.
- The initiation of combustion.
- A system for activating combustion in a combustion engine.
- Receptacle for a key used to start the engine in a vehicle.