The most common and most likely answer to this crossword clue is the 4 letter word INCA
I've seen this crossword clue in The Times
I
N
C
A
More clues leading to the result INCA
- S American coin cashier's taken in
- Old South American concerned with extremes in Colombia
- Old Peruvian in outskirts of Canberra
- Old American person’s home near California
- Tongue forming content of metal container
- Content of metal container is ancient tongue
- Old Peruvian employed in Turin cathedral
- Tongue all but swallowed by lion?
- Spain came to suppress them
- I can move around old empire
Buddy explains!

The straight part
We know that "S American" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case s american = inca.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 INCA mean?
INCA noun- Any of several species of hummingbirds in the genus Coeligena