Coffee makes you stronger, they say (7)
I believe the answer is:
robusta
'coffee' is the definition.
(type of coffee bean)
'stronger they say' is the wordplay.
'stronger' becomes 'robuster'.
'they say' shows a homophone (sound like).
'robuster' sounds like 'ROBUSTA'.
'makes you' is the link.
(Other definitions for robusta that I've seen before include "Here's coffee" , "One kind of coffee" .)