KanjiJLPT N2
Superfluous

superfluous, uselessness

Mnemonic

A crown rests on a workbench, declared superfluous. The king already owns a dozen — this one is pure excess. The carpenter shoves the superfluous crown aside, annoyed it hogs his workbench. 'Nobody needs a thirteenth crown!' he grumbles, tossing it in the scrap bin.
Additional thoughts
Picture a gaudy, unwanted crown cluttering a humble workbench — it doesn't belong, nobody asked for it, and it's just in the way. The crown literally sits atop the workbench, matching how 冖 sits atop 几.
Quick recall
A crown dumped on a workbench is superfluous — the king already has too many.

Details

The keyword for 冗 is superfluous. This kanji conveys the idea of something being excessive, redundant, or more than what is necessary. It often carries the nuance of being wordy, long-winded, or unnecessarily drawn out, as in speech or writing that goes beyond what is needed. By extension, it can also suggest something trivial or not essential.
On'yomi
じょう

Used in kanji

Used in vocab