phial n.

"vessel used for holding liquids," late 14c., from Medieval Latin phiola, from Latin phiala, from Greek phialē "flat vessel, dish, flat bowl for drinking or sacrificing," a loan-word of unknown origin. It also came to Middle English via Old French fiole "flask, phial" (12c.), hence the diversity of Middle English spellings (fiole,phiole,phial,fial,viole,vial,viele) and modern vial.