While the lists of words are nice, or I thought they were, there is definitely some trouble with the definitions. Defining a word with that word makes no sense.
However, that is not my most egregious complaint. As I was scrolling through the word lists that I thought were the ‘nice’ part of PowerThesaurus I was reading antonyms for rigorous and found away with the fairies, atypical and bedridden. Are you suggesting that people who are atypical, mentally ill (that is an ableist term but I understand that it is a thesaurus) or in bed for a time cannot be rigorous? If that is something people are suggesting, and in our ableist society I understand where they got the idea, but they are in fact, wrong. Disabled people, not all, but many, have the capacity to be rigorous. Should they care to be.
You might think it is just how people define words. But it is your app. Of course you don’t seem to mind about the definitions. Why would you mind about a bit of ableism?