堆
duī · HSK 5
pile
📚 earth radical 土 + 隹 (short-tailed bird) = pile of earth; measure word for heaps
堆 means a pile or heap, and serves as a measure word for things gathered in clumps (一堆书 = a pile of books). The 土 radical signals earth/mound; 隹 gives the sound. Use it for stacked or clustered quantities.
堆 — earth 土 + bird 隹 (phonetic)
堆 is a phono-semantic compound. The earth radical 土 gives the meaning, suggesting a mound or pile of soil, while 隹 (a short-tailed bird) supplies the sound. Originally it referred to a heap of earth, and today it broadly means a pile or to stack things up.