The most common and most likely answer to this crossword clue is the 7 letter word BUCKLER
I've seen this crossword clue in Financial Times
B
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More clues leading to the result BUCKLER
Buddy explains!
The straight part
We know that "Armour" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case armour = buckler.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 BUCKLER mean?
BUCKLER noun- One who buckles something.
- A kind of shield, of various shapes and sizes, held with a hand (usually the left) for protecting the front of the body. In the sword and buckler play of the Middle Ages in England, the buckler was a small shield, used, not to cover the body, but to stop or parry blows.
- A shield resembling the Roman scutum. In modern usage, a smaller variety of shield is usually implied by this term.
- One of the large, bony, external plates found on many ganoid fishes.
- The anterior segment of the shell of a trilobites.
- A block of wood or plate of iron made to fit a hawse hole, or the circular opening in a half-port, to prevent water from entering when the vessel pitches.
- To shield; to defend.