KanjiJLPT N1
Accumulate

collect, gather, be in arrears

Mnemonic

A violent storm unleashes torrents of rain across the lowlands. The surrounding mountains detain every drop, trapping the floodwaters with no outlet. Day after day the water keeps rising, and an enormous lake begins to accumulate in the basin below.
Additional thoughts
Picture a landlocked valley where storms keep dumping rain that has nowhere to go—detained by the terrain—so it pools higher and higher. The physical image of water accumulating reinforces both radicals naturally.
Quick recall
A storm dumps rain that the mountains detain, letting water accumulate into a vast lake.

Details

The keyword for 溜 is accumulate. This kanji conveys the idea of things gathering, collecting, or pooling together over time. It can refer to the physical pooling of water or other liquids in one place, as well as the more abstract sense of things building up or amassing, such as stress, savings, or work. The character captures both the gradual nature of collection and the resulting state of having gathered a significant amount.
On'yomi
りゅう
Kun'yomi
た.まる、たま.る、た.める、したた.る、たまり、ため