The most common and most likely answer to this crossword clue is the 6 letter word REGINA
I've seen this crossword clue in The Guardian
R
E
G
I
N
A
More clues leading to the result REGINA
- Sovereign taking a nation in the wrong direction
- Queen‘s in study endlessly drinking alcohol
- Queen, one in outrage, flipping
- Queen sees a country in recession
- Queen‘s troubled reign before onset of anarchy
- Remarkable reign associated with a queen
- Dreadful rage in Queen facing opposition in court
- Queen in Canadian capital
- This queen would be overthrown in a republic in Africa
- Recreated a reign of Roman queen
Buddy explains!

The straight part
We know that "Queen" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case queen = regina.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.