This tutorial can be applied to MS Word 2013. Follow these steps in order to find the dictionary.
Start with selecting a certain word which you would like to look up and press “Review” and then “Define”.
Alternatively, you can do the same by right-clicking your selected word and pressing “Define”.
Now, you can read the word definition in opened up dictionary.
It may happen that the dictionary has not been installed yet. In such a case, instead of the word definition, you will find the list of various dictionaries which are available for downloading. Check the list and pick up the one which suits you the most and then press “Download”. Once, the dictionary has been installed, Microsoft Word 2013 will open it automatically every time when you press the command “Define”.
If you want to see the list with synonyms, you will need to press “Review” and “Thesaurus”, or simply right-click and press the option “Synonyms”.