Flagrate (flah-GRAH-tay) conjures a burning, fiery rope in the air, which can be directed in any shape or direction the caster chooses. A mark will linger as well and fade with time.
Hermione Granger used this spell to mark doors in the Department of Mysteries in 1995.
This spell, along with the Gemino Curse, was cast on every object inside the Lestrange Vault at Gringotts Wizarding Bank to prevent anyone from stealing them.
Etymology
Flargo is Latin, meaning to blaze.