The most common and most likely answer to this crossword clue is the 5 letter word FARSI
I've seen this crossword clue in The Times
F
A
R
S
I
More clues leading to the result FARSI
- Persian's not half prescient
- Persian is taking service back
- Asian language, second on distant island
- Asian language, remote, is from the East
- For this modern language, is a service set up?
- Language is a repetitive problem that should be anticipated by football chiefs
- Semi-hyperopic tongue!
- Language from distant part of NZ
- d. People for whom a long way is up
- Language from afar signified
Buddy explains!

The straight part
We know that "Persian" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case persian = farsi.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.