The most common and most likely answer to this crossword clue is the 9 letter word BALDACHIN
I've seen this crossword clue in The Times
B
A
L
D
A
C
H
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N
More clues leading to the result BALDACHIN
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The straight part
We know that "canopy" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case canopy = baldachin.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 BALDACHIN mean?
BALDACHIN noun- A rich, embroidered brocade used for clothing in the Middle Ages, the web being gold and the woof silk.
- A canopy suspended over an altar or throne, originally made of this fabric; a ciborium.
- A building in form of a canopy, or a crown supported by pillars for the covering of an altar; a canopy carried over the host in Roman Catholic countries.