As stated up there in my comment, Heatran is an ideal counter to Clefable. Standard Clefable sets have nothing to hit it. All you really need to do is keep it relatively healthy and you can stop Clefable easily. I suggest Heatran over other Steel types, and there is two reasons for this. The first is its Fire immunity, as most good Clefable sets run Flamethrower.
Definition. The genitive is the case (or function) of an inflected form of a noun or pronoun showing ownership, measurement, association, or source. Adjective: genitival. The suffix -'s on nouns is a marker of genitive case in English.
genitive. adj. 1. (Grammar) denoting a case of nouns, pronouns, and adjectives in inflected languages used to indicate a relation of ownership or association, usually translated by English of. n.