Chabad.org — English translation + Rashi
Torah Temimah (Berachos 57a, Tanna de-vei R. Yishmael): why are they called “kishu’im”? Because they are as hard (kashim) on the body as swords.
English: The school of R. Yishmael taught: Why are they called kishu’im? Because they are as hard on the body as swords.
Etymology of the vegetable list — the names themselves carry a warning about harm.
Even the remembered “delicacies” of Egypt are marked as damaging.