I wish we could edit on word online
Wenjun Gong (MSFT Product Team) commented
Thanks for your feedback. If you have edit authority of the online Word document (for an example, the document you created or somebody else shared with you with edit authority), you should be able to edit the document online. If you are in view mode, you can click "Edit Document" button then select "Edit in Word Online" option in the drop down list.
Hope this helps and please let me know if you have more question.
Thanks and please keep posting more ideas!