Two essentials for roasting a dragon? (8)

I believe the answer is:

spitfire

I'm a little stuck... Click here to teach me more about this clue!

'dragon?' is the definition.
(thesaurus)

I cannot understand how the rest of the clue works.

(Other definitions for spitfire that I've seen before include "WWII warplane" , "Quick-tempered person" , "Wartime fighter aircraft" , "World War Two fighter aircraft" , "WW2 fighter aircraft" .)

I've seen this clue in The Times.

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