Adjective to describe things that don't have any potential in them for initiating any kind of activity

Question

There are living things in this world: humans, animals, trees. One their prominent characteristic is that they all can move in some way on their own.

There are lifeless things that yet can still show some movement or some sort of activeness: robots, cars, waterfalls, lightning, rain, wind, tornadoes, etc.

And there are also things that don't usually show any movement or activity: stones, rocks, tables, pens, a sheet of paper, a glass, a cup, etc.

What adjective should I use to describe the things in the third group? That is, the things that don't have any potential in them for initiating any kind of activity?

Inactive, idle, passive, or anything else?

Answer 1

One word is immotile:

[Merriam-Webster]

: lacking motility

a free-form sculpture that manages to suggest movement while remaining an immotile object

(In contrast, motile means "exhibiting or capable of movement.")

---

However, I can think of no word that only means incapable of initiating movement—as well as never having been capable of movement in the past.

A battery-operated toy, for instance, can move. Once its battery dies, it is now motionless, immotile, and inanimate. But if the battery is replaced, movement is possible again . . .

Answer 2

You could consider inanimate:

• inanimate
  1: not animate:
  a : not endowed with life or spirit • an inanimate object
  b : lacking consciousness or power of motion • an inanimate body
  (M-W)

• inanimate
  possessing none of the characteristics of life that an animal or plant has:
  an inanimate object
  (Cambridge Dictionary)