Vanishing Spell

The Vanishing Spell makes something vanish (not just become invisible, but go away completely)

References from the canon

•  When Colin was taking his picture and asking him to sign it, Harry wished he knew a good Vanishing Spell to escape the embarassment (CS6)
• Another form of this spell actually makes things go away. Neville did this by mistake to one of the legs of his desk when McGonagall announced that, in spite of the attacks on students and the banishment of Albus Dumbledore and Hagrid, they would still be given their exams (CS16).
• Bill Weasley used this to make a stack of scrolls disappear while cleaning up after a meeting of the Order of the Phoenix during Harry's first night at number twelve, Grimmauld Place (OP5).
• Snape used the Vanishing Spell to get rid of Harry's less-than-perfect attempt at a Draught of Peace (OP12).
• The fifth years had to practice Vanishing spells for some of their first Transfiguration homework that year (OP13).
• Fifth years work on the Vanishing Spell in Transfiguration, starting with snails and then working their way up to mice (OP15).
• According to Professor McGonagall, Vanished objects go "into non-being, which is to say, everything" (DH30).