The Disarming Charm (incantion: Expelliarmus) is a spell that knocks the target's wand out of their hand and/or attacks them.

User Casted on When
Severus Snape Gilderoy Lockhart 1992
Remus Lupin Harry Potter 1994
Severus Snape Sirius Black 1994
Cedric Diggory Viktor Krum 1995
Neville Longbottom Parvarti/Padma Patil 1996
Many Dumbledore's Army Members Mobile Death Eaters/other members 1995-1996