The way to get to the bottom of things (9)
I believe the answer is:
downwards
'the' is the definition.
I can't tell whether this definition defines the answer.
'way to get to the bottom of things' is the wordplay.
'way' becomes 'w' (Compass direction - West).
'to get' is a charade indicator (letters next to each other).
'to the bottom' becomes 'down'.
'of things' becomes 'ards' (I can't explain this - if you can you should believe this answer much more).
'w' after 'down' is 'downw'.
'downw'+'ards'='DOWNWARDS'
Can you help me to learn more?
(Other definitions for downwards that I've seen before include "as seen in feather-bedded hospitals?" , "Towards a lower point" , "Direction of the pull of gravity" .)