The most common and most likely answer to this crossword clue is the 6 letter word SOLEMN
I've seen this crossword clue in The Times
S
O
L
E
M
N
More clues leading to the result SOLEMN
- Single month, November or August?
- Only second half of hymn is formal and dignified
- . Man disembowelled by fish is in grave state
- Only fellow not given a grave
- Only chap to avoid a grave
- Fish man gutted in earnest
- Serious, lonesome and heartless man
- Only man to lose heart sober
- Glum single bloke is disheartened
- Thus useless person without love becomes pompous
Buddy explains!

The straight part
We know that "August" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case august = solemn.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 SOLEMN mean?
SOLEMN adjective- Deeply serious and somber.
- Somberly impressive.
- Performed with great ceremony.
- Sacred.
- Gloomy or sombre.