Condition in Which a Balanced System Is Unchanging

This page is the CodyCross answer for the clue below from Physics, Group 1892, Puzzle 4 (Inertia and Entropy).

Question is: Condition in Which a Balanced System Is Unchanging

and the answer is: STABLE

Word Meaning:

STABLE — A building, wing or dependency set apart and adapted for lodging and feeding (and training) ungulates, especially horses.

Definitions from Wiktionary.