Crossword Genius

Deteriorate, having obtained no marijuana (2,2,3)

Ross

I believe the answer is:

go to pot

'deteriorate' is the definition.
(thesaurus)

'obtained no marijuana' is the wordplay.
'obtained' becomes 'got' ('get' can be a synonym of 'obtain').
'no' becomes 'o' (resembles 0 - 'no' can mean 'zero').
'marijuana' becomes 'pot' ('pot' can be a synonym of 'marijuana').
'got'+'o'+'pot'='GO TO POT'

'having' acts as a link.

(Other definitions for go to pot that I've seen before include "Become ruined" , "Reveal signs of neglect" , "Deteriorate completely - ready to be cooked?" , "Deteriorate, like food ready for cooking?" , "If you want a cup of tea" .)

I've seen this clue in The Telegraph.
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