"Drone" is a very general expression for a wide range of vehicles, and it is mostly used by the press and outsiders. Lately, the word has been picked up by Marketing to give model aircraft a more fancy label. People who design and use unmanned aircraft tend to use more specific expressions.
Will it return?
The earliest use of unmanned vehicles was for one-way missions, either as flying targets or as flying bombs. While the flying bombs are today mostly called cruise missiles, the term "drone" initially was reserved for the unarmed variety, serving as targets. Note that technical limits would not allow the early models to make a controlled landing. They were one-way vehicles. Only later, with better radio control, could target drones be reused.
Will it fly autonomously?
With the immense increase in computing power, the pilot did not have to be in the loop all the time, and unmanned vehicles learned to land to be reused. The term "drone" never was used by those who designed and built them in order to make a distinction between their sophisticated unmanned vehicles and those dumb, one-way drones. The whole combination of ground station, data relay and flying vehicle became an unmanned system to stress the multi-component nature of these things. The vehicle itself is now called a UAV for unmanned aerial vehicle, or UCAV in case of armed unmanned combat aerial vehicles. Other functions gave rise to names like HALE (high altitude, long endurance) which doesn't even mention the unmanned nature of these craft. But they never are called drones by their makers.
Does it carry ordnance?
If you answer all three questions "No", it is a drone. Strictly speaking, if one question has a positive answer, there is a better term for it. Note that the first question also excludes model aircraft but also more modern target drones! Taking the examples in your question, only the third picture shows a drone (if it will be shot at later and there is a distinct likelihood that it doesn't land in one piece).
Use of the term by the general public
Unfortunately, the more specific terms have never left the ghetto of specialist technical terminology, and the press has decided to call all unmanned aircraft "drones". It is similar to the word "hacker" which originally described computer experts and now is used for criminals by the public.