Dear Si++ , dear bro : 

We are talking about Zarf  fiil [ ulaç] not  isim fiil.  That is very simple..I don´t know why you don´t want to see that simple fact ? You are a clever man.

OK then "Zarffiil" should not be called "gerund", right? Because the gerund definition of English talks about a verbal form that functions as a noun (not adverb).

Then it (i.e. "Zarffill") is called "gerundive" in English as I earlier said in this thread.

Grammatical terms are flexible. They must be because languages are different. There is a tradition of calling Turkish zarf fiiller gerunds and even though it is not quite logical  -  I understand it now thanks to si++  -  it does not harm as long as we agree. Similar inaccuracies occur in the grammar of many languages.

In my insignificant opinion leaving the gerund naming to isim fiil like in English and Latin would have made more justice to the structure of Turkish in which verbal nouns play an extraordinary role. But we play with these rules now.