Great loss of liquid for flushing toilet (8)
I believe the answer is:
waterloo
'great loss' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'liquid for flushing toilet' is the wordplay.
'liquid' becomes 'water' (water is a kind of liquid).
'for' means one lot of letters go next to another.
'flushing toilet' becomes 'loo' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'water'+'loo'='WATERLOO'
'of' is the link.
Can you help me to learn more?
(Other definitions for waterloo that I've seen before include "Seminal European battle of 1815" , "Lose a decisive contest - meet your . . . . . . . . as Napoleon did" , "Losers may meet theirs" , "19th century battle" , "Meet one's - -" .)