Mountains in some volume (5)
I believe the answer is:
atlas
This might be a double definition.
'mountains' is the first definition.
(I've seen this before)
'some volume' is the second definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'in' is the link.
Can you help me to learn more?
(Other definitions for atlas that I've seen before include "Chart book" , "I carry a huge weight" , "Map collection" , "travel book" , "N. African mountains; a Titan" .)