Tube for liquid in mine covering domestic source of electricity (7)
I believe the answer is:
pipette
'tube for liquid' is the definition.
'pipette' can be an answer for 'tube' (I've seen this before). I am unsure of the 'for liquid' bit.
'mine covering domestic source of electricity' is the wordplay.
'mine' becomes 'pit' (down the pit).
'covering' is an insertion indicator.
'domestic' becomes 'pet' (I can't explain this - if you can you should give a lot more credence to this answer).
'source of' suggests taking the first letters.
The first letter of 'electricity' is 'e'.
'pit' enclosing 'pet' is 'pipett'.
'pipett'+'e'='PIPETTE'
'in' is the link.
Can you help me to learn more?
(Other definitions for pipette that I've seen before include "laboratory equipment" , "Calibrated tube" , "Item of chemistry lab glassware" , "Eye-dropper" , "Item of chemists' equipment" .)