Fearfully impressed (6)

I believe the answer is:

afraid

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'impressed' is the definition.
Both the definition and answer are adjectives. Maybe you can see an association between them that I don't see?

I cannot understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for afraid that I've seen before include "Regretfully" , "Alarmed, fearful" , "Not confident" , "cowardly" , "Timorous" .)

I've seen this clue in The Globe and Mail.

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