Holding water, it can make you rich, pet (7)
I believe the answer is:
pitcher
'holding water it' is the definition.
I can't judge whether this definition defines the answer.
'can make you rich pet' is the wordplay.
'can make you' is an anagram indicator.
'rich'+'pet'='richpet'
'richpet' is an anagram of 'PITCHER'.
Can you help me to learn more?
(Other definitions for pitcher that I've seen before include "Baseball player - bowl" , "that can hold his drink" , "Baseball bowler and container for liquid" , "Earthenware jug" , "Does one throw the vessel?" .)