Why does the gemara make a limud of the posuk saying tekallel with 2 lamuds instead of takel with one? The noun is kelala and the verb is l'kallel. There doesn't seem to be any noun as kal for a curse or verb as takel for to curse in the Hebrew language. How can you make a limud on a word that doesn't exist?
The Gemara seems to indicate that it actually is a word. This is also apparent from Tosfos earlier (DH "Klili") and the Meforshim who discuss the Gemara (see Margaliyos Hayam end of 76a whose comments seem to support that this is a regular word).
All the best,