stagnant
adj.describing water that is not moving and often smells bad, or a situation that is not growing or changing.
adj.showing no activity, movement, or growth; often used to describe bodies of water that lack a current or flow. Frequently applied metaphorically to economies or careers that have ceased to develop.
“The air in the old room felt heavy and stagnant.”
“Mosquitoes often breed in stagnant water that collects in old tires after a heavy rain.”
“Economists warned that without significant investment in new technology, the nation's industrial sector would remain stagnant while its global competitors continued to innovate.”
Often follows linking verbs like 'become', 'remain', or 'stay'.
“AI researchers often talk about “AI Springs” and “AI Winters”—periods when progress in the field is either booming or stagnant.”
From French stagnant, from Latin stagnans, present participle of stagno (“to form a pool of standing water”).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.