The most common and most likely answer to this crossword clue is the 11 letter word COMMANDMENT
I've seen this crossword clue in The Daily Telegraph
C
O
M
M
A
N
D
M
E
N
T
More clues leading to the result COMMANDMENT
Buddy explains!

The straight part
We know that "One of ten" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one of ten = commandment.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 COMMANDMENT mean?
COMMANDMENT noun- A divinely ordained command, especially one of the Ten Commandments.
- Something that must be obeyed; a command or edict.
- The act of commanding; exercise of authority.
- The offence of commanding or inducing another to violate the law.