The most common and most likely answer to this crossword clue is the 8 letter word MEMBRANE
I've seen this crossword clue in The Guardian
M
E
M
B
R
A
N
E
More clues leading to the result MEMBRANE
- Layer of fibre in widely shared image
- Viral content contains detailed class film
- European doctor managed to cut this writer’s skin
- Film politician almost embracing artist close to breakdown
- This person repeatedly eats grain to make bodily tissue
- Widely shared image includes fibre layer
- Marvel’s left note for Charlie during wrap for film
- Film shows yours truly drinking barmen’s rum
Buddy explains!

The straight part
We know that "film" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case film = membrane.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 MEMBRANE mean?
MEMBRANE noun- A flexible enclosing or separating tissue forming a plane or film and separating two environments (usually in a plant or animal).
- A mechanical, thin, flat flexible part that can deform or vibrate when excited by an external force.
- A flexible or semi-flexible covering or waterproofing whose primary function is to exclude water.