Physicist’s important piece bearing fruit (7)
I believe the answer is:
hawking
'physicist's' is the definition.
(I've seen this before)
'important piece bearing fruit' is the wordplay.
'important piece' becomes 'king' (king is a kind of chess piece. I am not sure about the 'important' bit.).
'bearing' means one lot of letters go next to another.
'fruit' becomes 'haw' (I've seen this before).
'king' put after 'haw' is 'HAWKING'.
Can you help me to learn more?
(Other definitions for hawking that I've seen before include "Falconry - "Brief History" author" , "Cosmologist attracted to 6 [BLACKHOLE] s" , "clearing his throat noisily" , "Physicist" , "Peddling" .)