The most common and most likely answer to this crossword clue is the 5 letter word SWEAR
I've seen this crossword clue in The Sunday Telegraph
S
W
E
A
R
More clues leading to the result SWEAR
- Promise singular sport
- Some problems — we argue and use bad language
- Small display showing promise
- Curse small effect of erosion
- Saint has to tolerate curse
- Use four-letter word: the “corn” in Cornwall?
- Curse Cornish listener
- Use bad language in opening to summer sport
- Promise to put the last of exhibits at the front
- Promise from Sunday Sport
Buddy explains!

The straight part
We know that "E.g. bloody" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case e.g. bloody = swear.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 SWEAR mean?
SWEAR verb- To take an oath, to promise.
- To use offensive, profane, or obscene language.
- A swear word.
- To be lazy; rest for a short while during working hours.
- Heavy.
- Top-heavy; too high.
- Dull; heavy; lazy; slow; reluctant; unwilling.
- Niggardly.
- A lazy time; a short rest during working hours (especially field labour); a siesta.