Spitfire, perhaps (7)

I believe the answer is:

fighter

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'spitfire' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe they are linked in a way I don't understand?

I don't understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for fighter that I've seen before include "Professional boxer - a person with determination" , "Fast military aircraft" , "Combatant, battler" , "Plane" , "Combat aircraft" .)

I've seen this clue in the Evening Standard.

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