The most common and most likely answer to this crossword clue is the 10 letter word EXPLETIVES
I've seen this crossword clue in The Guardian
E
X
P
L
E
T
I
V
E
S
More clues leading to the result EXPLETIVES
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 = expletives.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 EXPLETIVES mean?
EXPLETIVES noun- A profane, vulgar term, notably a curse or obscene oath.
- A word without meaning added to fill a syntactic position.
- A word that adds to the strength of a phrase without affecting its meaning.