phial /ˈfaɪəl/noun 1verb 1forms 5 noun1 •(old-fashioned) A bottle or other vessel for containing a liquid; originally any such vessel, especially one for holding a beverage; now (specifically), a small, narrow glass bottle with a cap used to hold liquid chemicals, medicines, etc.AA Is a glass phial filled vvith mercury to the superficies DD, or thereabout. — 1682 verb1 •To keep or put (something, especially a liquid) in, or as if in, a phial. formsphialed · phialled · phialing · phialling · phials