Webster's Revised Unabridged Dictionary · 1913

Panacea

Panacea , noun

[Latin, from Greek pana`keia from panakh`s all-healing; pa^s pa^n, all + 'akei^sqai to heal.]

1.
A remedy for all diseases; a universal medicine; a cure-all; catholicon; hence, a relief or solace for affliction.
2.
(Botany) The herb allheal.