The site does state that only the first 100 words are listed.
The examples submitted by B & B give the following results at your site, Chambers, & Quick Solve here:
r???i??  - 400 / 407 / 205
?o??i?? - 1211 / 1168 / 682
?e??i??? - 1211 / 814 / 469
Hardly  realistic expectations with that many ?s.   Duh!
On the other hand, quite a number of results, unusual words, did not link to a definition. 
The best was Dictionary.com,  with Yahoo a distant second.
Wikipedia doesn't handle plurals well, or upper case. Your links always create a capitalized link for Wiki.
Perhaps Wictionary would be a better choice.  I got better results there.
Also, consider a link to OneLook.
http://www.onelook.com/
Good luck with your project.