The most common and most likely answer to this crossword clue is the 4 letter word PAIL
I've seen this crossword clue in The Daily Telegraph
P
A
I
L
More clues leading to the result PAIL
- Water-carrier — originally plain Aquarius in Latin
- Turning to drink, holding one large container
- Friend carrying one bucket
- Pothead to be sick in bucket
- Ice originally put in china bucket
- By the sound of it, white container for liquid
- Bucket of friend I put inside
- Container that’s white, by the sound of it?
- I take friend out in vessel
- Playmate carrying one bucket …
Buddy explains!

The straight part
We know that "Bucket" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case bucket = pail.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 PAIL mean?
PAIL noun- A vessel of wood, tin, plastic, etc., usually cylindrical and having a handle -- used especially for carrying liquids, for example water or milk; a bucket (sometimes with a cover).
- (In technical use) A closed (covered) cylindrical shipping container.