The most common and most likely answer to this crossword clue is the 7 letter word MIRRORS
I've seen this crossword clue in The Guardian
M
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R
R
O
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Buddy explains!
The straight part
We know that "Reflects/what is deceptive with smoke" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case reflects/what is deceptive with smoke = mirrors.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 MIRRORS mean?
MIRRORS noun- A smooth surface, usually made of glass with reflective material painted on the underside, that reflects light so as to give an image of what is in front of it.
- An object, person, or event that reflects or gives a picture of another.
- A disk, website or other resource that contains replicated data.
- A mirror carp.
- A kind of political self-help book, advising kings, princes, etc. on how to behave.
- Of an event, activity, behaviour, etc, to be identical to, to be a copy of.
- To create something identical to (a web site, etc.).
- To reflect, as in a mirror.