The kanji 昨 primarily signifies "yesterday" or "the previous day." It refers to the day immediately preceding the current day and is crucial for discussing events and occurrences from the recent past. The meaning focuses on the concept of time passed.

・On-yomi (音読み): サク (saku) ・Kun-yomi (訓読み): None, as the primary meaning is expressed through the on-yomi.

⚫︎ 昨日（きのう） Translation: Yesterday ⚫︎ 昨夜（さくや） Translation: Last night ⚫︎ 昨年（さくねん） Translation: Last year

The kanji 昨 is a phono-semantic compound (形声文字 - keisei moji). The semantic component is 日 (nichi, hi), meaning "sun" or "day," indicating the temporal aspect. The phonetic component is 乍 (saku), which contributes the sound. Thus, the character combines the element of time with a phonetic element to represent "yesterday."