The kanji 波 primarily represents "wave" or "waves". It refers to the undulating movement of water, or more generally, any recurring pattern of rise and fall. It encapsulates the idea of a rhythmic or cyclical motion. It can also imply something that is spreading or influencing.

・On-yomi (音読み): ha ・Kun-yomi (訓読み): nami

⚫︎ 波乗り Translation: Surfing ⚫︎ 津波 Translation: Tsunami (tidal wave) ⚫︎ 電波 Translation: Radio waves

The kanji 波 is a phono-semantic compound (形声文字). The left side is the water radical, 氵 (also written as 水, which is the radical for water), indicating its relation to water. The right side is 皮 (read hi), which originally meant "skin" or "bark". The original form was likely meant to suggest the surface of the water, like the skin, which forms waves. Over time, the meaning shifted to specifically mean waves.