One flier finishing a little after another (6)

I believe the answer is:

beetle

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'one' is the definition.
Both the answer and definition are adjectives. Maybe they are linked in a way I don't understand?

I can't explain the remainder of the clue.

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(Other definitions for beetle that I've seen before include "Insect with protective forewings" , "Insect with hard-wing covers" , "Let bee buzz around this insect" , "pest" , "Beater" .)

I've seen this clue in the Evening Standard.

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