The most common and most likely answer to this crossword clue is the 9 letter word LOATHSOME
I've seen this crossword clue in The Daily Telegraph
L
O
A
T
H
S
O
M
E
More clues leading to the result LOATHSOME
- Dreadful old hat daughter's thrown out not entirely repellent
- Highly offensive males too awful, husband admitted
- Horrible hot meal, so disgusting
- Horrible to behold: a book about Hamas extremists
- Vile profanities in opera lacking appeal
- Criminal shot a mole – that’s abhorrent
- Look in to restrain son being obnoxious
- Very unpleasant Latin curses over setter
- To Holmes, a criminal is repugnant
- MOs to heal sick and sickening
Buddy explains!
The straight part
We know that "Nasty" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case nasty = loathsome.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 LOATHSOME mean?
LOATHSOME adjective- Highly offensive; abominable, sickening.