I don\'t know whether StackOverflow covers NLP, so I am gonna give this a shot.
I am interested to find the semantic relatedness of two words from a specific domain, i.e. \"imag
You might want to take a look at the book Opinion mining and sentiment analysis.
If you are only interested in similarity of words and phrases, this survey paper may help you: From Frequency to Meaning: Vector Space Models of Semantics