United States military pension applications (both veterans and their spouses) are usually made “under” a specific pension act. The name of that act and date of its passing is usually referenced in their initial paperwork.
See if you can find the text of that act by searching for it online. Read the act. Your ancestor believed the met the qualifications. For the veteran that meant in terms of their service. For the spouse, it meant that the veteran met the service terms of the act and that the spouse met the marriage requirements of the act.
That information could be helpful in your research–particularly if the amount of information known on the ancestor is minimal.