增
zēng · HSK 5
increase
➕ 曾 (ceng, layer/once) + 土 (earth) — pile on more soil, increase
The phonetic 曾 carries the zeng sound and hints at layers stacking up; 土 (earth) grounds the meaning. Adding earth layer by layer is how a mound grows — hence add, increase, gain.
增 — earth 土 + 曾 (phonetic, 'layer/repeat')
A semantic-phonetic compound: 土 ('earth') gives the meaning, while 曾 supplies the sound and hints at 'layered, piled up.' The original sense was piling earth higher and higher, which generalized to 'increase, add to.' 曾 itself depicts a tiered steamer, reinforcing the idea of stacking.