A wet part available in most kitchens (3,5)
I believe the answer is:
tap water
'most kitchens' is the definition.
Although both the answer and 'kitchens' are nouns, they are not in the same form of the noun.
'a wet part available in' is the wordplay.
'part' indicates anagramming the letters (I've seen 'parts of' mean this).
'available' becomes 'tapr' (I can't justify this - if you can you should believe this answer much more).
'in' indicates putting letters inside.
'a'+'wet'='awet'
'awet' anagrammed gives 'wate'.
'wate' inserted within 'tapr' is 'TAP-WATER'.
Can you help me to learn more?
(Other definitions for tap water that I've seen before include "Cold running drink?" , "Drink from mains" , "Ordinary drink" , "Vital liquid from a sink unit" , "simple drink" .)