Hangul syllable Jan

It can mean a cup, a serving, or part of a word. As a noun, 잔 names a small drinking vessel; after a number, it counts one serving. In 잔소리 (“nagging”), 잔- means “small or trivial,” not a cup.

The vessel predates the spelling: Korean archaeological sources record pottery cups from the Neolithic. Hangul—the Korean writing system whose letters combine into syllable blocks—was promulgated in 1446; that dates the writing system, not the word. A 1474 Joseon ritual manual includes a cup diagram. In Korean writing with Chinese characters, 盞 is used for the vessel word 잔. A 2023 Korean–Chinese study pairs it with 杯 (whose Korean reading is written 배) as a vessel noun and counting word; the study reports that modern Chinese no longer uses 盞 in the cup sense, while Korean retains it as a drink counter.