Two shortly become confused in silly talk (7)
I believe the answer is:
twaddle
'silly talk' is the definition.
(I've seen this before)
'two shortly become confused' is the wordplay.
'shortly' means to remove the last letter.
'become confused' becomes 'addle' (I've seen this before).
'two' with its last letter taken off is 'tw'.
'tw'+'addle'='TWADDLE'
'in' is the link.
(Other definitions for twaddle that I've seen before include "Pretentious or silly talk" , "Senseless talk" , "Hot air" , "Foolish speech/writing" , "Foolish speech" .)