The word **哪门子** is a colloquial, rhetorical interrogative phrase formed by combining the interrogative pronoun **哪** (nǎ, "which") with **门子** (ménzi), where **门** metaphorically means "category," "type," or "branch (of study/family)," and **子** is a nominal suffix. Literally meaning "which category of," it functions not as a genuine question but as a strong, dismissive rhetorical device to express disbelief, rejection, or to negate the premise of a statement—akin to saying "what kind of nonsense..." or "what on earth..."—thereby conveying that the thing in question is unreasonable, unfounded, or simply doesn't belong to any acceptable category.