The term 'overwhelming quantity' can be described by two crossword solutions: SEA (3 letters) and BARRAGE (7 letters). SEA is an acronym for 'Surface, Engage, Attack', which is a military tactic used to overwhelm an enemy with a large number of forces. A BARRAGE is a large number of objects or people that are sent at the same time in order to overwhelm a target. Both terms are used to describe an overwhelming quantity of something.