Container for drink: mother's in ruins! (7)
I believe the answer is:
thermos
'container' is the definition.
(I know that thermos is a type of vacuum bottle)
'mother's in ruins' is the wordplay.
'in ruins' indicates an anagram.
'mothers' with letters rearranged gives 'THERMOS'.
'for drink' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for thermos that I've seen before include "Flask trade mark" , "Container to retain heat" , "Heat-retaining flask for mothers" , "Vacuum flask for mothers" .)