Virgulilla, which is Spanish for something like ‘an accent or mark.’ Usually it refers to what in English we call the tilde (which probably also derives from the Spanish*), but can also mean any diacritical mark resembling a comma, line or dash. The tilde originates from Latin as a “mark of suspension” in place of omitted letters in abbreviations (e.g., Anno Domini would be Aº Dñi). And, according to one source, medieval scribes abbreviated the phoneme “nn” as “n~” in order to distinguish it from “m.” Placing the mark above the n saved space (vellum was expensive).
We have an English cognate in ‘virgule,‘ which means ‘slash’ (and for typographers it means the keyboard slash, as opposed to the solidus, or fraction-bar slash). Virgule comes to us from the Latin virgula, a diminutive for virga, or ‘rod.’ The illa suffix in Spanish is also a diminutive.
Tilde itself has a link to diminution: the Spanish verb tildar means ‘to add tildes where needed,’ but it also means ‘to diminish or denigrate’ when applied to a person.
*Según el Real Academia Española: “tilde: virgulilla o rasgo que se pone sobre algunas abreviaturas…”