The most common and most likely answer to this crossword clue is the 7 letter word CUIRASS
I've seen this crossword clue in Independent
C
U
I
R
A
S
S
More clues leading to the result CUIRASS
Buddy explains!
The straight part
We know that "plate" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case plate = cuirass.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 CUIRASS mean?
CUIRASS noun- A piece of defensive armor, covering the body from the neck to the girdle.
- The breastplate taken by itself.
- To cover with defensive armor; to armor-plate.