Length of blade yet to turn up for saw (4)

I believe the answer is:

eyed

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'saw' is the definition.
(I've seen this before)

I don't understand the remainder of the clue.

(Other definitions for eyed that I've seen before include "Watched warily" , "Saw" , "Stared at" , "Vegetable" , "Ogled" .)

I've seen this clue in The Telegraph.

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