The most common and most likely answer to this crossword clue is the 4 letter word WAIN
W
A
I
N
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.
What does WAIN mean?
WAIN noun- A wagon; a four-wheeled cart for hauling loads, usually pulled by horses or oxen.
- To carry.
- (Derry) A collective word usually for children.