The most common and most likely answer to this crossword clue is the 4 plus 1 plus 3 letter word HALF A TON
I've seen this crossword clue in The Guardian
H
A
L
F
A
T
O
N
More clues leading to the result HALF A TON
Buddy explains!
The straight part
We know that "some weight" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case some weight = half a ton.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.