Poison Words are words or phrases that trigger suspicion with the search engines about a website. But it was widely believed that these can affect the page rank of a website. These ad sense words are pure webmaster speculation.
Effects of Poison Words:
Poison Words are the one, specified by google: when used in the description, title tag can affect the page rank of a website. Not only that, when these phrases are used in web pages where google ad sense ads are displayed, the ads will be stopped by google filters. Usually the only remedy would be to remove them.
It is believed that, in order to achieve search engine optimization (SEO), one must avoid using any "Poison Words". Some claim that the page ranks get affected drastically, but others say it’s a myth.
The way-out
Out of the methods suggested by people, first would be to find these poison words in a webpage, then carefully removing them with alternate text. The next method is to convert it as images. This becomes handy in the words in blog sites, where webmaster has no control over user submitted blogs. So that the search engine crawlers go blind at these words that are in image format.
The best way would be to carefully choose the content for the title, description tags. Even though so many websites list the poison words, most of them are related to adult, profanity content. Even some medical terms are also listed as poison words. All these claim that it will affect the page rank. But in reality poison words doesn’t seem to affect the PR of a website.