The most common and most likely answer to this crossword clue is the 3 plus 7 letter word WET BLANKET
I've seen this crossword clue in Financial Times
W
E
T
B
L
A
N
K
E
T
More clues leading to the result WET BLANKET
- I'm no fun, as a result of sweaty night?
- Spoiler of fun is clear in unfortunate tweet
- Have accident in bed? No joy for him
- Possible result of sleeping outdoors? Misery!
- Misery, western and Aliens — nothing between them
- Killjoy in battle knew to yield
- Spoilsport being vacuous in silly tweet
- Killjoy melting snow could be described as such
- Dreary pessimist knew battle is lost
- With void between two spacemen, there’s misery
Buddy explains!
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.
Crossword Answer definitions
WET BLANKET verb- To disparage, belittle, or remove the satisfaction and joy from; to act as a wet blanket towards.