Recliner wrote:

Isn't that what those yellow drones someone linked to last week are for?

They don't fly, so they're not drones.

Is there an actual definition for a drone that says it must fly ?
In the past I have heard the term used to describe unmanned submersibles,
they are similar in that like the flying ones they can move along vertical
axis as well as horizontal so perhaps that is what differentiates a drone
from something else but when checking that such submersibles are still
being called drones I came across a few examples of “land drones” mainly
being developed for military use .
eg
https://sites.google.com/site/umainelanddrone10/

Such things used to be just unmanned ground vehicles so is the reality is
that the term drone is now being used to encompass other objects that are
remote controlled and its use in language hasn’t settled yet.

GH