The most common and most likely answer to this crossword clue is the 7 letter word BOLDEST
I've seen this crossword clue in The Times
B
O
L
D
E
S
T
More clues leading to the result BOLDEST
Buddy explains!

The straight part
We know that "Most brave," is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case most brave, = boldest.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 BOLDEST mean?
BOLDEST adjective- Courageous, daring.
- Visually striking; conspicuous.
- (of typefaces) Having thicker strokes than the ordinary form of the typeface.
- Presumptuous, forward or impudent.
- Naughty; insolent; badly-behaved.
- Full-bodied.
- Pornographic; depicting nudity.
- Steep or abrupt.