philtre
/ˈfɪltr/ or /ˈfɪltər/Definitions
1. noun
a charm or love potion, often in the form of a drink or food, used in medieval folklore to attract a person to the one who offers it; a device or means used to achieve a particular end, especially an illicit or deceitful one.
“The medieval knight believed that the princess’s philtre would make her fall in love with him.”