Broadcaster gets large, then thin (7)
I believe the answer is:
slender
'thin' is the definition.
(I know that thin can be written as slender)
'broadcaster gets large' is the wordplay.
I cannot really see how this works, but
'large' could be 'l' (eg in clothes sizes) and 'l' is found within the answer.
The remaining letters 'sender' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'then' acts as a link.
Can you help me to learn more?
(Other definitions for slender that I've seen before include "remote" , "Shakespearean character" , "Slight in form" , "Thin or narrow" , "Gracefully thin and elegant" .)