Awful bore in Lausanne is quite contrary (12)

I believe the answer is:

unreasonable

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'awful' is the definition.
Both the answer and definition are adjectives. Perhaps there's an association between them I don't understand?

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

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(Other definitions for unreasonable that I've seen before include "Immoderate" , "Not fair" , "dear?" , "Beyond acceptable limits" , "Unacceptable" .)

I've seen this clue in The Irish Times.

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