The most common and most likely answer to this crossword clue is the 7 letter word CAMPERS
I've seen this crossword clue in The Daily Telegraph
C
A
M
P
E
R
S
More clues leading to the result CAMPERS
Buddy explains!

The straight part
We know that "Holidaymakers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case holidaymakers = campers.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 CAMPERS mean?
CAMPERS noun- A person who camps, especially in a tent etc.
- A motor vehicle with a rear compartment for living and sleeping in.
- A person who stays in one spot during a first-person shooting game, to guard an item etc.