加深
jiā shēn · HSK 7
to deepen
🌊 加深 = 加 (add) + 深 (deep) = add depth = to deepen
加 — force 力 + mouth 口
加 is traditionally analyzed as a compound of 力 (strength) and 口 (mouth), suggesting boasting or exaggerating one's effort with words. From this it extended to the meaning 'to add' or 'increase'. Today it is used broadly for addition, both literal and figurative.
深 — water radical 氵 + 罙 (phonetic, depth)
深 combines the water radical 氵 with 罙, which depicts a hand reaching into a cave or hollow. Originally it described deep water, then broadened to mean 'deep' in any sense — distance, color, or feeling. The 氵 gives the meaning, while 罙 hints at both sound and the idea of reaching far in.