Sozzled, rich upper-class lady taking water under pressure? (9)
I believe the answer is:
hydraulic
'taking water under pressure?' is the definition.
(hydraulic means relating to water under pressure)
'sozzled rich upper-class lady' is the wordplay.
'sozzled' indicates an anagram.
'upper-class' becomes 'u' (similar in meaning).
'rich'+'u'+'lady'='richulady'
'richulady' anagrammed gives 'HYDRAULIC'.
(Other definitions for hydraulic that I've seen before include "Sort of brake" , "Driven by liquid under pressure" , "regarding piped water?" , "moved under pressure" , "Relating to liquids under pressure" .)