龥 is essentially obsolete — an archaic variant of
籲 (traditional) /
吁 (simplified, in the 'appeal' sense), meaning 'to call out, to appeal earnestly'. The modern equivalent is the common compound
呼吁 'to appeal, call upon (the public)' — used routinely in news writing about petitions and public causes.
龥 itself appears only in classical citation, paleographic dictionaries, and the rare specialist Chinese-character lookup.
