公约
gōngyuē · HSK 7
convention
📜 公约 = public (公) + agreement (约); a shared pact
公 means public or communal, 约 means agreement or pact. Together 公约 is a joint pledge or convention — an agreement binding a group, like a treaty or community charter.
公 — eight 八 + private 厶
Originally an ideograph showing 八 (to divide) over 厶 (private/self), depicting the act of splitting away from selfish interest. The combination came to mean 'public' or 'fair,' the opposite of private. It later extended to senses like 'duke,' 'lord,' and 'grandfather.'
约 — silk radical 糹/纟 + ladle 勺
约 combines the silk radical 糹 with 勺 (ladle), which provides the sound. Originally it referred to binding or tying with silk cords, from which came the meanings 'to bind by agreement,' hence 'pact, appointment,' and later 'approximately' (a loose, tied-up estimate).