The most common and most likely answer to this crossword clue is the 10 letter word GALVANISED
G
A
L
V
A
N
I
S
E
D
Buddy explains!
The straight part
We know that "coated with another metal" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case coated with another metal = galvanised.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 GALVANISED mean?
GALVANISED adjective- Of metal, coated with zinc as a form of protection against rust.
- Having been subjected to galvanism; electrified.
- To coat with a thin layer of metal by electrochemical means.
- To coat with rust-resistant zinc.
- To shock or stimulate into sudden activity, as if by electric shock.
- To electrify.
- To switch sides between Union and Confederate in the American Civil War.