Infinity cryptically written as NES (11)

I believe the answer is:

endlessness

I'm a little stuck... Click here to teach me more about this clue!

'infinity' is the definition.
(thesaurus)

'cryptically written as nes' is the wordplay.
I cannot quite see how this works, but
an anagram of 'nes' is 'sne' which is within the answer.
This explanation may well be incorrect...

Can you help me to learn more?

(Other definitions for endlessness that I've seen before include "Interminable quality" , "Interminability" , "No conclusion!" .)

I've seen this clue in The Times.

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