Argumentum ex culo
From RationalWiki
Argumentum ex culo is the act of arguing by way of non sequitur, ad hockery, and/or bullshit in a desperate attempt to shore up a blatantly untenable argument. The derivation is from Latin and need not be explained to anyone who's ever bothered to learn a Romance language.
As a general rule, if something stinks about the argument, there's a good chance it's an argumentum ex culo.

