What is malicious prosecution in tort?

malicious prosecution,i would say, is an action for damages against the plaintiff by the defendant on various grounds....but solely out of malice,ill-will,spite....when i mentioned various grounds i meant that they were just excuses that the defendant used to prosecute the plaintiff whereas in fact his main reason was malice. here,the plaintiff and defendant can be old enemies or even competetors in the industrial realm or otherwise.Also, this case of malicious prosecution will not be justified by facts....rather it will be a a case brought about just to injure he plaintiff.