The most common and most likely answer to this crossword clue is the 8 letter word FILAMENT
I've seen this crossword clue in The Times
F
I
L
A
M
E
N
T
More clues leading to the result FILAMENT
- Wire that's flimsy insulated by paper wrapping at home
- Strand most of non-professional troops in sound
- Wire one on limping nag, initially, into this paper
- There’s sign of heat around one
- Feeble end of bulletin in suitable thread
- Fibre shown by female, one getting keen
- Fibre Formula 1 regret
- Film Etna erupting — fibre’s needed
- If mantle breaks, get part from an electric bulb
- Cable broadcast neat film
Buddy explains!

The straight part
We know that "Wire" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case wire = filament.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 FILAMENT mean?
FILAMENT noun- A fine thread or wire.
- Such a wire, as can be heated until it glows, in an incandescent light bulb or a thermionic valve.
- A massive, thread-like structure, such as those gaseous ones which extend outward from the surface of the sun, or such as those (much larger) ones which form the boundaries between large voids in the universe.
- The stalk of a flower stamen, supporting the anther.
- A continuous object, limited in length only by its spool, and not cut to length.