Solanine is a glycoalkaloid poison found in species of the nightshade family within the genus Solanum, such as the potato, the tomato, and the eggplant

Raw potatoes certainly are mildly toxic, it’s not just undigestible starches.

Seriously, which part of this is sarcasm?

“to talk about disparaginly or negatively” is the verb form of “slur”, the noun form is a little bit different. You can slur Elon Musk by calling him a privileged phony, but that doesn’t make “privileged” or “phony” slurs themselves.

A more fitting definition of “slur” in the sense that it is used here is “a derogatory or insulting term applied to particular group of people”. “Cis” is not a derogatory term, just like “trans”, “white”, or “Black” are not themselves derogatory terms. You can probably imagine some actual slurs that apply to each of these groups (tbh I’m having a hard time thinking of one for “cis”), but I don’t intend to write them out here.