The most common and most likely answer to this crossword clue is the 7 letter word BIVOUAC
I've seen this crossword clue in The Daily Telegraph
B
I
V
O
U
A
C
Buddy explains!

The straight part
We know that "camp" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case camp = bivouac.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 BIVOUAC mean?
BIVOUAC noun- An encampment for the night, usually without tents or covering.
- Any temporary encampment.
- A temporary shelter constructed generally for a few nights.
- The watch of a whole army by night, when in danger of surprise or attack.
- A structure formed by migratory ants out of their own bodies to protect the queen and larvae.
- To set up camp.
- To watch at night or be on guard, as a whole army.
- To encamp for the night without tents or covering.