The kanji 汐 primarily represents "tide" or "the time of the tide". It conveys the concept of the rise and fall of the sea, the movement of water due to the gravitational pull of the moon and sun. It can also refer to the sea water itself.

・On-yomi (音読み): せき (seki) ・Kun-yomi (訓読み): しお (shio)

⚫︎ 干潮（かんちょう） Translation: Low tide / Ebb tide ⚫︎ 汐風（しおかぜ） Translation: Sea breeze ⚫︎ 汐入（しおいり） Translation: (place name, literally "tide enters")

The kanji 汐 is a phono-semantic compound (形声文字, keisei moji). It is composed of two parts: 水 (mizu, water) as the semantic component indicating the meaning "water," and 夕 (yū, evening) as the phonetic component, suggesting the sound and also potentially referencing the time of day, as tides often change. The association with 夕 might also relate to the colors of the sea at sunset.