Block web page containing a specific word in safari

I would like to know if there is any mac safari plugin to block any web page containing a specific word in its url or in its content.

For example, suppose we take the word 'abc', the following link must be blocked : wwww.dfrrraabc.com

A web page containing 'abc' in its content must also be blocked.

I don't know if a plugin like this already exists for safari.