Crossword Genius

Calibration seen on fish (5)

Ross

I believe the answer is:

scale

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'calibration' is the definition.
(thesaurus)

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(Other definitions for scale that I've seen before include "Deposit formed in a kettle or on teeth" , "Climb; flake of skin" , "Measure" , "plaque" , "An ordered series of units for measurement purposes" .)

I've seen this clue in The Mirror.
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