The most common and most likely answer to this crossword clue is the 8 letter word BURNSIDE
I've seen this crossword clue in The Daily Telegraph
B
U
R
N
S
I
D
E
Buddy explains!

The straight part
We know that "US general" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case us general = burnside.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 BURNSIDE mean?
BURNSIDE noun- (especially in plural) A moustache, with whiskers on the cheeks but with no beard on the chin