咠 ('to whisper in the ear') is archaic and not used independently in modern Chinese. It survives as the phonetic in 缉 (to track down / hem), 辑 (to compile / edit), 揖 (to bow with cupped hands), and 葺 (to repair a roof).
memory
A mouth 口 brought up to an ear 耳: leaning in to whisper a secret — exactly what 咠 draws.