The most common and most likely answer to this crossword clue is the 6 letter word PLURAL
I've seen this crossword clue in The Guardian
P
L
U
R
A
L
More clues leading to the result PLURAL
- Place on Russian mountain range in which sheep remains the same
- More than one found in river to the east of Poland
- More than one place on river
- More than one comrade touring Lima, an old city
- Involving more than one in place on river
- Man left on river? More than one concerned
- More than one almost tempt friend to come round
- Many extremely powerful Russian banks hold it
- More than one friend securing draw, mostly
- Having more than one place on river
Buddy explains!

The straight part
We know that "More than one concerned" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case more than one concerned = plural.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 PLURAL mean?
PLURAL noun- (grammar) The plural number.
- (grammar) A word in the form in which it potentially refers to something other than one person or thing; and other than two things if the language has a dual form.
- Consisting of or containing more than one of something.
- Pluralistic.