Separate from icy mass, save large bears sleeping in here? (4)
I believe the answer is:
cave
This clue could be a double definition.
'separate' is the first definition.
The definition and answer can be both related to thinking as well as being verbs in their base form.
Perhaps there's an association between them I don't understand?
'icy mass save large bears sleeping in here?' is the second definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'from' is the link.
Can you help me to learn more?
(Other definitions for cave that I've seen before include "Aladdin, Fingal, had one" , "Natural underground space" , "Subject of speleology" , "Large grotto" , "Hollow in a rock" .)