Vulnera Sanentur

Vulnera Sanatur is a spell used to heal injuries ranging from minor cuts to deep gashes. The incantation, which sounds "almost like song," (possibly not entirely in accord with the book,) must be repeated three times in a row to have maximum effect. The first time it is used, the flow of blood eases up; the second time causes the wounds to knit; the third time removes most visible injuries near-instantly. The victim would still require medical treatment, but if dittany is applied immediately, scarring can be avoided.

Known uses

 * Severus Snape (who was likely the inventor) used this spell to heal Draco Malfoy's wounds after Harry Potter cast Sectumsempra on him during a duel in the second-floor girls' lavatory in 1997.

Etymology
Vulnera Sanatur derives from Latin vulnero, "wound," and sanare, "to heal."

Appearances

 * Harry Potter and the Half-Blood Prince
 * Harry Potter and the Half-Blood Prince (film)