The meaning in terms of a singular object has evolved from the meaning in terms of a kit of objects, e.g. Feuerzeug was originally a flint stone and a fire striker, Nähzeug (sewing kit) and Sportzeug (sports equipment) are still being used in that manner. Werkzeug is a bit more tricky, as it can be the term for a singular item, e.g. a screwdriver, and a bunch of tools, e.g. all tools contained in a toolbox, while still the plural Werkzeuge exists.
However, I admit, that “stuff” to me as a non native English speaker carries more the meaning of Kram (collection of items with no specific purpose) than Zeug (with some purpose).
Edit: Fahrzeug and Flugzeug were made up in the early 20th century to combat the influence of foreign languages in German, so I wouldn’t interpret too much into the meaning of the parts of these composita.
The meaning in terms of a singular object has evolved from the meaning in terms of a kit of objects, e.g. Feuerzeug was originally a flint stone and a fire striker, Nähzeug (sewing kit) and Sportzeug (sports equipment) are still being used in that manner. Werkzeug is a bit more tricky, as it can be the term for a singular item, e.g. a screwdriver, and a bunch of tools, e.g. all tools contained in a toolbox, while still the plural Werkzeuge exists.
However, I admit, that “stuff” to me as a non native English speaker carries more the meaning of Kram (collection of items with no specific purpose) than Zeug (with some purpose).
Edit: Fahrzeug and Flugzeug were made up in the early 20th century to combat the influence of foreign languages in German, so I wouldn’t interpret too much into the meaning of the parts of these composita.