The kanji 旬 [旬] primarily represents a period of ten days or a decadal cycle. It often refers to a unit of time, specifically one-third of a month. This period can also be associated with the peak season or the best time for something, such as harvesting crops or enjoying a particular food.

・On-yomi (音読み): シュン ・Kun-yomi (訓読み): None, or used as a component in longer words.

⚫︎旬の野菜 Translation: Seasonal vegetables ⚫︎旬の魚 Translation: Fish in season ⚫︎上旬 Translation: The first ten days of the month

The kanji 旬 [旬] is a phono-semantic compound (形声文字, けいせいいもじ). The left side is 月, つき meaning "moon" or "month", and the right side is 勹, つつみ meaning "to wrap" or "to surround". The original meaning of 旬 [旬] was "ten days", which is related to the lunar cycle, because it is close to the period from a new moon to the first quarter, which is about ten days. Over time, it came to be associated with the best time or peak period for something, reflecting the concept of a cycle reaching its fullness.