通告
tōng gào · HSK 7
to announce
📢 通 communicate/pass-through + 告 to tell = put word through to all = announce
通 means to pass through or communicate; 告 means to tell or inform. Together they mean sending a notice through to everyone — a public announcement. Note tōng is first tone (flat), gào is fourth tone (sharp drop).
通 — 辵 (辶) walk + 甬 yǒng (phonetic)
通 is a semantic-phonetic compound. The 辶 (chuò) component means 'walk' or 'movement', giving the meaning of going through or passing. 甬 (yǒng), originally depicting a hanging bell or a path, supplies the sound. Together they convey 'to pass through, communicate, connect'.
告 — ox 牛 (top) + mouth 口
Originally a pictograph showing an ox with something on its head, possibly a yoke or sacrificial marker, combined with 口 (mouth) to suggest announcing or reporting. The character came to mean 'to tell' or 'to announce,' as in making a formal declaration. Today it commonly appears in words like 告诉 (to tell) and 报告 (report).