Sorry but I don't think the dictionary was correct.
It seems to be a google definition.

I am in a FB discussion on this too.

I tried looking up more definitions. This comes from:
http://allegory.happykidsschool.com.tw/ ... s-allegory

Definitions

a) a story, poem, or picture which can be interpreted to reveal a hidden meaning, typically a moral or political one. (Google)
b) a story in which the characters and events are symbols that stand for ideas about human life or for a political or historical situation; a symbolic representation of something else (Merriam-Webster)
c) a literary device in which characters or events in a literary, visual, or musical art form represent or symbolize ideas and concepts (Wikipedia)

When I did English Lit, the definition of Allegory was more b & c.

Sorry but I don't think the dictionary was correct.
It seems to be a google definition.

[...]

a) a story, poem, or picture which can be interpreted to reveal a hidden meaning, typically a moral or political one. (Google)

"can be interpreted"?
That defines nothing.
Anything "can be interpreted" as anything. Anyone can say "but I interpret it that way". It's meaningless. (Perhaps what you might expect from Google ...)

And I'd say "reveal a hidden meaning" is too vague, too.

The b) and c) definitions that you quote, talk about symbols and representing or symbolizing ideas. That's more substantial, it's then possible to discuss whether there really are such symbols present in a text, not just look for interpretations.

I saw somebody on the net saying about allegory (probably quoting from The Oxford Dictionary of Literary Terms) that it “involves a continuous parallel between two (or more) levels of meaning in a story, so that its persons and events correspond to their equivalents in a system of ideas or a chain of events external to the tale.”

I think the continuous parallel is missing when you try to look at Narnia as allegory. There are details in Narnia that correspond to equivalents in our world, but it would be too much to say that "its persons and events" correspond in that way. Too many of them don't.

I would say that there are glimpses of allegory in Narnia, but that the Chronicles as such aren't allegory. Lewis might have written allegory whether he meant to or not, but most of the time he didn't. What he meant to do, was to write about "supposals" - suppose that Christ would come to a world of animals, how would he then come and what would he do?

No, I don't think Narnia is an allegory. There are certainly some biblical parallels in the Chronicles like Aslans rising from the dead, and Narnia's creation among other. Lewis was of course a Christian and like every author his worldview and beliefs are reflected in his works.

But my understanding of an allegory is that it's a one-to-one relationship with some idea or thing in the real world like Pilgrim's Progress or Animal farm. which Narnia definitely isn't. Lewis himself said Narnia was supposal of a another world and Aslan a supposal of what if Christ came to that world, but this time in the form of a lion, and was not meant to be taken as allegory.

I would say that there are glimpses of allegory in Narnia, but that the Chronicles as such aren't allegory. Lewis might have written allegory whether he meant to or not, but most of the time he didn't. What he meant to do, was to write about "supposals" - suppose that Christ would come to a world of animals, how would he then come and what would he do?

Agree. There are several glimpses of it being an allegory. Parts of it I see it as an allegory, and other parts as an incredible story from one awesome imagination. Regardless, one of the most beautiful things about these stories is how they relate to different people, and at different times. When I was younger they meant something totally different to me than they do today. People are going to see what they need to see at the time of reading it. Its a beautiful thing. So yes, parts are very much allegorical, where other parts are just amazing stories. Either way I love that I get to enjoy it and learn different things each time!