KanjiJLPT N3
Reside

reside, to be, exist, live with

Mnemonic

An old man plants a flag in the ground and declares: 'This is where I Reside!' He's been here so long, the flag has turned old and ragged, yet he refuses to move—this patch of earth is his home, and he'll grow old beneath that flag forever.
Additional thoughts
Picture a weathered elder staking his claim with a flag—the flag (尸) drapes over old (古) like a roof over a long-established home. The permanence of old age and the territorial mark of the flag together evoke settled, rooted dwelling.
Quick recall
An old man plants a flag where he'll reside forever.

Details

The keyword for 居 is reside. This kanji conveys the idea of living in a place, dwelling, or being situated somewhere. It encompasses both the physical act of inhabiting a location and the broader sense of occupying a position or remaining in a state. It is used in contexts relating to one's home, residence, or simply being present and settled in a particular place.
On'yomi
きょ、こ
Kun'yomi
い.る、-い、お.る