KanjiJLPT N2
Slippery

slippery, slide, slip, fail exam

Mnemonic

A storm drenches the road where a skeleton lies sprawled. The rain makes its bones incredibly slippery—every time you grab one, it shoots from your grip like a bar of soap. The skeleton slides downhill through the storm, rattling as it glides across the slick pavement, impossible to catch.
Additional thoughts
Picture grabbing a wet femur bone in a downpour—it squirts right out of your hands. The storm provides the water, the skeleton provides the smooth hard surface. Together they create the ultimate slippery scenario.
Quick recall
A storm soaks a skeleton whose bones become impossibly slippery, sliding away from your grasp.

Details

The keyword for 滑 is slippery. This kanji conveys the idea of a smooth, frictionless surface that is difficult to grip or stand on without losing one's footing. It encompasses the broader sense of smoothness, gliding, and sleekness, as well as the notion of something being slick or lubricated. By extension, it can also describe someone who is cunning or evasive, much like trying to hold onto something slippery that keeps escaping one's grasp.
On'yomi
かつ、こつ
Kun'yomi
すべ.る、なめ.らか