تَفْعِيلٌ

[verbal noun of فعّل] is used by IJ as metonymically signifying The scanning of a verse; because the names of the measures of its feet, all of them, have the letters ف and ع and ل for constituents, as when you say فَعُولُنْ and مَفَاعِيلنْ and فَاعِلَاتُنْ and فَاعِلُنْ &c. (TA.)