ulciscor.

Disputed. Traditionally, the word has been connected with ulcus (“sore”), with the term following a semantic development of "to grow sores (against someone)" > "to avenge one's griefs." De Vaan considers this etymology uncompelling. The LIV suggests a possible derivation from Proto-Indo-European *h₂l̥ksḱéti, from *h₂elk- (“to protect, ward off”). However, De Vaan considers this etymology semantically uncompelling. Alternatively, he suggests a derivation from *h₃elh₁- (“to destroy”), which at some point would have been enlarged with a k-extension. Ancient Greek ὀλέκω (olékō, “to kill, destroy”) may showcase a similar extension of the same root. Höfler, however, considers De Vaan's proposal "hardly convincing," and Schrijver states that the connection with the aforementioned Greek word "has little to commend itself."