How do you search for content, not words?
The general principle about finding text based on meaning similarity is called distributional semantics. The main idea is that words with a similar meaning statistically tend to co-occur with the same context words. This is the basis for many standard tasks like topic modeling, word sense disambiguation/induction, and generally for everything related to semantics.
The problem you're describing is essentially information retrieval: given a query expressed as one or several words, find the &quot;documents&quot; in a corpus which are semantically similar to this query.
[edit] Depending what the data looks like, you might be interested in the more specific task of semantic textual similarity.