The most common and most likely answer to this crossword clue is the 10 letter word SWEARWORDS
I've seen this crossword clue in The Guardian
S
W
E
A
R
W
O
R
D
S
More clues leading to the result SWEARWORDS
Buddy explains!

The straight part
We know that "oaths" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case oaths = swearwords.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 SWEARWORDS mean?
SWEARWORDS noun- A word considered taboo and impolite or offensive.