Flask in bag right at the bottom (10)
I believe the answer is:
nethermost
'the bottom' is the definition.
(I've seen this before)
'flask in bag right' is the wordplay.
'flask' becomes 'thermos' (thermos is a kind of flask).
'in' is an insertion indicator.
'bag right' becomes 'net' (I've seen this in other clues. I am not sure about the 'right' bit.).
'thermos' put within 'net' is 'NETHERMOST'.
'at' is the link.
Can you help me to learn more?
(Other definitions for nethermost that I've seen before include "at the bottom of the pile" , "located in lowest position" .)