The term 'Water Under the Bridge' is a metaphor for something that has happened in the PAST and is no longer relevant. The crossword solutions for this term are MOAT (4 letters), PAST (4 letters), BYGONES (7 letters), STREAM (6 letters), and ANCIENTHISTORY (14 letters). MOAT refers to a deep, wide ditch filled with water that surrounds a castle or other structure, symbolizing the idea of something that is no longer relevant. PAST is a reference to the idea that the event has already happened and is now in the PAST. BYGONES is a term used to describe something that has been forgotten or is no longer relevant. STREAM is a metaphor for the idea that the event has passed by, like a STREAM of water. Finally, ANCIENTHISTORY is a reference to the idea that the event is so far in the PAST that it is now considered ancient history.