The most common and most likely answer to this crossword clue is the 8 letter word APPOSITE
I've seen this crossword clue in The Guardian
A
P
P
O
S
I
T
E
More clues leading to the result APPOSITE
- Area, quiet river location, is suitable
- Suited work secretary repulsed by spot
- Suitable computer program opening, initially, internet location
- Fitting program on old web page
- Suitable program location to store zero
- Suitable situation outside Italy secured by primate
- Apt to take off clothes after embracing one
- Suitable place to carry parrot? On the contrary
- A quiet river on location – just the job!
- Apt to make an assumption that dons mock
Buddy explains!

The straight part
We know that "Fitting" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fitting = apposite.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 APPOSITE mean?
APPOSITE noun- That which is apposite; something suitable.
- Strikingly appropriate or relevant; well suited to the circumstance or in relation to something.
- Positioned at rest in respect to another, be it side-to-side, front-to-front, back-to-back, or even three-dimensionally: in apposition.
- Related, homologous.