The most common and most likely answer to this crossword clue is the 4 letter word BASH
I've seen this crossword clue in Financial Times
B
A
S
H
More clues leading to the result BASH
- Party hit with embarrassment having ditched leader
- Expression of disgust about leader of socialist party
- I don't give a fig about southern party
- Party hosted by club, a shindig
- Party hit
- Black stuff left in barbie box
- Hit wood on Birkdale's first
- Go forward right away
- Party remains behind leader in bewilderment
- Republican leaves loud party
Buddy explains!

The straight part
We know that "party" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case party = bash.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 BASH mean?
BASH noun- A large party; gala event.
- An attack that consists of placing all one's weight into a downward attack with one's fists.
- To strike heavily.
- To collide.
- To criticize harshly.
- To masturbate.
- To abash; to disconcert or be disconcerted or put out of countenance.