Unable to delete Word file in an Android Device

Yes, you are doing everything "right" (if you can call it this way). As there is no better way right now.

I've already lost hopes waiting for Microsoft to fix this.

Deleting and reinstalling this application basically equals (not exactly, but still) to clearing it's data.

Google Search Docs will not resolve this problem, as applications cant access internal data of other applications.

It amazes me that in Dec 2019 this is still not resolved. Seems can still not delete individuallly I am now using it as just a means of temporarily downloading files from the Internet or attachments from emails to read then (in layman's terms as I am not technical) I go to Recent, click on my photo, which takes me to Account. I go to settings (or any other way you can get to settings) then scroll down to reset office and click reset. This clears Everything on my phone. This is the only way I can see but it is clearly not what is wanted from Microsoft. Come on Microsoft sort this out!! 🙈

You need to delete and reinstall the app. In the meanwhile, delete the file using google search docs. You could also try deleting the app memory although i hadn't tried that.

It either means that you cleared Cache and not Data, or you did something else. As clearing Data will remove that info.