The most common and most likely answer to this crossword clue is the 9 letter word ARGENTINE
I've seen this crossword clue in The Times
A
R
G
E
N
T
I
N
E
More clues leading to the result ARGENTINE
- South American autocrat's first entering in confusion
- A right nice guy meeting hip earl from Cordoba?
- South American bloke at home in most of district
- El Papa is one right into delegate in Rome finally
- Some regular gent, in essence, from South America
- Barges into mines stripped of silver
- Doctor entering behind a South American
- Silvery toff I introduced to composer
- Foreign inhabitant and government stopping a payment in Spain
- Unexpectedly entering with a South American
Buddy explains!

The straight part
We know that "South American" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case south american = argentine.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 ARGENTINE mean?
ARGENTINE noun- Any osmeriform fish of the genus Argentina, especially the European argentine, Argentina sphyraena.
- A siliceous variety of calcite, or lime carbonate, having a silvery-white, pearly lustre, and a waving or curved lamellar structure.
- White metal coated with silver
- Containing or resembling silver.