The most common and most likely answer to this crossword clue is the 7 letter word LLANERO
I've seen this crossword clue in Financial Times
L
L
A
N
E
R
O
More clues leading to the result LLANERO
- Everyone turned on tyrant, one from the plains
- Everybody rejected boss who fiddled – a cowboy
- New driver on road runs over plainsman
- Plain black interpreted by Raphael, with everyone cycling in the foreground
- One found in plain overall in shift getting number for volume
- Plain inhabitant wants ring back, left short of $100 by notorious fiddler
Buddy explains!

The straight part
We know that "one from the plains" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one from the plains = llanero.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 LLANERO mean?
LLANERO noun- A plainsman; a South American cattle-herder or cowboy, especially in Venezuela and Colombia.