Ten thousand horses standing mute is, after all, a thing to grieve.
Tips
history
喑 is not used independently in modern Chinese. It survives in the idiom 万马齐喑 (a deathly, oppressive silence, literally 'ten thousand horses all mute'). The phonetic is 音.
register
Archaic and literary only, alive mainly inside that one idiom, not in everyday speech.
