KanjiJLPT N2
Waist

loins, hips, waist, low wainscoting

Mnemonic

The moon hangs so low tonight you need to bend at the waist just to see it through your window. Each night the moon sinks lower and you need to fold deeper at the waist — soon you're doing full backbends just to catch a glimpse.
Additional thoughts
Picture yourself bending further every night, your waist becoming the hinge between you and the sinking moon. The desperate need intensifies the image.
Quick recall
You need to bend your waist lower each night to glimpse the sinking moon.

Details

The keyword for 腰 is waist. This kanji refers to the midsection of the human body between the ribs and the hips, the area commonly known as the waist or lower back. It is central to posture, movement, and physical support, and by extension it can also convey the idea of a pivotal or central point of something, much as the waist serves as the body's core axis.
On'yomi
よう
Kun'yomi
こし

Used in vocab