The most common and most likely answer to this crossword clue is the 7 letter word BISMUTH
B
I
S
M
U
T
H
Buddy explains!

The straight part
We know that "metal" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case metal = bismuth.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 BISMUTH mean?
BISMUTH noun- A chemical element (symbol Bi) with an atomic number of 83: a brittle silvery-white metal.
- A single atom of this element.