The kanji 郵 primarily represents "postal service," "mail," or "post." It's directly related to the concept of sending and receiving letters, packages, and other forms of communication through an organized system.

・On-yomi (音読み): ユウ (yuu) ・Kun-yomi (訓読み): None (Generally, the on-yomi is used)

⚫︎ 郵便局 (yuubinkyoku) Translation: Post office ⚫︎ 郵便番号 (yuubinbangou) Translation: Postal code, Zip code ⚫︎ 郵送 (yuusou) Translation: Mailing, sending by mail

The kanji 郵 is a phono-semantic compound (形声文字). It combines two elements: ⚫︎ The phonetic component: 由 (yuu), which contributes the sound. 由 itself means "reason" or "cause," but in this compound, it primarily indicates the sound. ⚫︎ The semantic component: 阝 (a simplified form of 阜, which is radical 170 meaning “mound, hill”, but it is often used as a component of words related to places). The meaning is related to the location of the postal service. The postal service was established by the station near a big building in ancient times. The original meaning was related to the relays of horses used to send messages. The character evolved over time to represent the more modern postal system.