The way we hear Genesis (4)
I believe the answer is:
root
'genesis' is the definition.
(thesaurus)
'the way we hear' is the wordplay.
'the way' becomes 'route' (route is a kind of way).
'we hear' shows a homophone (sound like).
'route' is a homophone of 'ROOT'.
(Other definitions for root that I've seen before include "Lowest part of plant" , "Basic cause or origin" , "burrow" , "could be square" , "support" .)