I recently came across a blog post by a fellow SEO copywriter by the name of Liam Bailey that discusses the idea of Google now recognizing certain keyword synonyms, in addition to the keyword or keyphrase itself.
The example Bailey uses is with the terms overseas property and property abroad, citing that Google appeared to be recognizing each phrase as one in the same. And while the writer of this post provided no hard, concrete evidence that this was in fact the case, aside from personal assurance, as an SEO copywriter myself it really made me think.