Tea that's fizzy? It's a ridiculous pretence (7)
I believe the answer is:
charade
'a ridiculous pretence' is the definition.
(I've seen this before)
'tea that's fizzy? it's' is the wordplay.
'tea' becomes 'char' (I've seen this before).
'that's fizzy?' becomes 'ad' (I can't explain this - if you can you should believe this answer much more).
'it' becomes 'e' ('e' can mean 'electronic' which is similar to 'IT').
'char'+'ad'+'e'='CHARADE'
Can you help me to learn more?
(Other definitions for charade that I've seen before include "Pretence - travesty" , "Blatant deception" , "An absurd pretence, or a guessing game" , "Party game using mime" , "He'd a car but it was only empty pretence" .)