As far as Emil can stagger? (4)

I believe the answer is:

mile

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'can stagger?' is the definition.
The answer and definition can be both quantities as well as being singular nouns.
Perhaps they are linked in a way I don't understand?

'as far as emil' is the wordplay.
'emil' anagrams to 'MILE'.
However, I'm not sure how the anagram is indicated.

Can you help me to learn more?

(Other definitions for mile that I've seen before include "Imperial length" , "Stretch of road" , "1.61km" , "'A miss is as good as a ....'" , "5280 feet" .)

I've seen this clue in the Evening Standard.

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