Geller to land passing water (9)

I believe the answer is:

urination

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'passing water' is the definition.
'urination' can be an answer for 'water' (thesaurus). I'm not certain of the 'passing' bit.

'geller to land' is the wordplay.
'geller' becomes 'uri' (I can't justify this - if you can you should believe this answer much more).
'to land' becomes 'nation' (synonyms).
'uri'+'nation'='URINATION'

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

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