I agree totally with the Australian reviewer, Luke Stevens, though, to be fair, when I looked for Word 2013 apps I was told that there weren't any for my country (England)!
Consequently, as Mr Stevens points out, the dictionary recognizes neither the Queen's English nor Australian English - try putting "colour" or the like into it, let alone any of the Australian words he lists. It an American dictionary, for undemanding American users, and parochial for all that.
One would have thought that a program with a name like Word would be first and foremost concerned with establishing a powerful dictionary. The Oxford, which serves the Kindle so well, would have been a boon here. However, non-American and American academic users are currently stuck. The bing dictionary is superior to this one, but (as the reviews suggest) it is still lacking.