How do I make sure I get the definition for the right word sense if there is more than one meaning?

annarita__amenduni

At present, this is not something that is possible through the API.
However, if you are trying to retrieve the most common definition of a particular word, look out for the homograph Number attribute.
The structure of our data means that numbering cannot be sequential, but, in general, the lower the homographNumber, the more common the associated sense of the word is.