The most common and most likely answer to this crossword clue is the 7 letter word EARMARK
I've seen this crossword clue in The Times
E
A
R
M
A
R
K
More clues leading to the result EARMARK
- Designate weapon to be carried by English ship
- Flag with damage carried by European vessel
- Organ score set aside
- Single out animal sanctuary, English branch first
- Not initially expensive to get standard form of ID
- Set aside weapon stocked by English vessel
- Designate end of peace with a run on former currency
- Label organ feature
- A maker’s modified special label
- Mare disfigured on chest – symbol of 14?
Buddy explains!

The straight part
We know that "Flag" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case flag = earmark.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 EARMARK mean?
EARMARK noun- A mark or deformation of the ear of an animal, intended to indicate ownership.
- The designation of specific projects in appropriations of funding for general programs.
- A mark for identification; a distinguishing mark.
- To mark (as of sheep) by slitting the ear.
- (by extension) To specify or set aside for a particular purpose, to allocate.