You're talking about a type of argument and, more precisely, a type of fallacy. As described and as exampled in your question, the type could be one or more of several.
The most likely fallacy is the 'ad hominem':
An argument based on the perceived failings of an adversary rather than on the merits of the case; a logical fallacy that involves a personal attack.
(From "ad hominem" at About Education.)
This type, the 'ad hominem' most directly matches all the stipulations of your overall question.
However, the type of fallacy includes elements of the 'red herring', where the 'red herring' is the smokescreen offered by "ontology" which, as you describe it, may have no bearing on the argument.
A Red Herring is a fallacy in which an irrelevant topic is presented in order to divert attention from the original issue. The basic idea is to "win" an argument by leading attention away from the argument and to another topic.
(From The Nizkor Project, "Fallacy: Red Herring".)
To sum up, the word or phrase that best describes "an attempt to win an argument through the introduction of a concept or word that is intellectually outside the grasp of the opponent" is 'ad hominem argument', or 'ad hominem fallacy'. For the particular example you give of an 'ad hominem fallacy', the phrase 'red herring' also describes the argument.