The most common and most likely answer to this crossword clue is the 8 letter word REGULARS
I've seen this crossword clue in The Guardian
R
E
G
U
L
A
R
S
More clues leading to the result REGULARS
Buddy explains!
The straight part
We know that "Customers/who have taken vows" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case customers/who have taken vows = regulars.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 REGULARS mean?
REGULARS noun- A member of the British Army (as opposed to a member of the Territorial Army or Reserve).
- A frequent, routine visitor to an establishment.
- A frequent customer, client or business partner.
- A coffee with one cream and one sugar.
- Anything that is normal or standard.
- A member of a religious order who has taken the three ordinary vows.
- A number for each year, giving, added to the concurrents, the number of the day of the week on which the Paschal full moon falls.
- A fixed number for each month serving to ascertain the day of the week, or the age of the moon, on the first day of any month.