φ φ, φῖ, τό, indecl., twenty-first letter of the Gr. changes of φ: in Aeolic, Doric and Ionic the aspirate was often dropped, and φ became π, as in ἀσπάραγος σπόγγος σπυράς for ἀσφάραγος σφόγγος σφυράς, whereas the Attic sometimes used φ for π, as φανός φάτρα for πανός πάτρα. in Aeolic, Doric, and Ionic φ is sometimes put for θ, as φήρ φλάω for θήρ θλάω. older Poets sometimes treated φ as a double consonant, so that a short vowel before it becomes long by position, as in ὄφις, Ζεφύριος quasi ὄπφις, Ζεπφύριος.