More savage than the deep lake with the monster in The Waste Land (10)
I believe the answer is:
wilderness
'more savage than the deep lake' is the definition.
I can't tell whether this definition defines the answer.
'with the monster in the waste land' is the wordplay.
'with' is a charade indicator (letters next to each other).
'the monster in the waste' becomes 'wilder' (I can't justify this - if you can you should believe this answer much more).
'land' becomes 'ness' (ness is a kind of land).
'wilder' next to 'ness' is 'WILDERNESS'.
Can you help me to learn more?
(Other definitions for wilderness that I've seen before include "for a time unrecognised" , "Inhospitable region" .)