He goes under cask before woman with hesitation (9)

I believe the answer is:

tunneller

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'he goes under' is the definition.
The definition suggests a singular noun which matches the answer.

'cask before woman with hesitation' is the wordplay.
'cask' becomes 'tun' (tun is a kind of cask).
'before' says to put letters next to each other.
'woman' becomes 'nell' ().
'with' is a charade indicator (letters next to each other).
'hesitation' becomes 'er' (sound made while hesitating - um, er).
'tun'+'nell'+'er'='TUNNELLER'

Can you help me to learn more?

(Another definition for tunneller that I've seen is " Creator of underground passages".)

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

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