Actually it is nothing but when your irrelevant or less useful page comes up in SERP then your targeted ones. Usually happens in E commerce sites where you are going for Sony mobiles product XXX and Google is showing Sony mobile product XXB. Because of your unsorted or bad internal linking in the site.
Sorry Friend. Ur Answer irrelevant... Same keyword Target different page in your website so that ranking continue Fluctuate.This problem remove urgently
Its obvious i was talking about the same query, showing irrelevant page of your site. You did not understand my point. Anyway, I hope you got this.