KanjiJLPT N1
Surplus

surplus, besides

Mnemonic

After a long ride, you arrive at camp hauling mountains of supplies—far more than anyone needs. You grab a knife to slice open the extra sacks, revealing the absurd surplus: food, gold, and gear spilling everywhere like a piñata explosion.
Additional thoughts
Picture yourself on horseback, saddlebags overflowing ridiculously. The knife slashes sacks that burst with excess goods cascading out. Ride + Knife = Surplus.
Quick recall
A ride delivers way too much cargo; a knife splits the bags, unleashing the surplus.

Details

The keyword for 剰 is surplus. This kanji refers to an excess or remainder—something left over beyond what is needed or expected. It conveys the idea of having more than the required amount, an overabundance that goes beyond sufficiency. It is commonly associated with mathematical remainders as well as general notions of redundancy or superfluity.
On'yomi
じょう
Kun'yomi
あまつさえ、あま.り、あま.る

Used in vocab