伊

Used as a third-person pronoun or demonstrative “that one.”

Also functions as a particle in Classical Chinese.

By extension, used in transliterations, e.g. 伊大利 = Italy.

Phono-semantic compound:

人 (사람 인, “person”) — semantic, indicating a human or pronoun.

尹 (다스릴 윤, yǐn) — phonetic, providing the sound i / yī.

Thus the character originally denoted a person, later generalized into a pronoun “he, she, that.”

伊他 (이타) — he, that man

伊始 (이시) — from the beginning

伊川 (이천) — a place name, also name of the Neo-Confucian scholar Cheng Yi (程伊川)

伊斯蘭 (이슬람) — Islam (transliteration)

Classical Chinese: common as a third-person pronoun, especially in early texts.