"Anti-Muggle pranksters ...We had two last week, one in Wimbledon, one in Elephant and Castle. Muggles are pulling the flush and instead of everything disappearing - well, you can imagine. The poor things keep calling in those - pumbles, I think they're called - you know, the ones who mend pipes and things."
-- Arthur Weasley on using an Anti-Jinx for reguritating toilets (OP7)
Anti-Jinx spells are used to reverse Jinxes.
References from the canon
From the Web
"Anti-Jinx" on Harry Potter Wiki