Stagnant means still, and smelling of standing water. A stagnant pond, stagnant air, stagnant and green.
Water goes stagnant when nothing moves it: oxygen falls, algae take over and the smell follows. Figuratively a stagnant economy or career is one going nowhere, and the metaphor is exact — the problem is the absence of movement rather than decline. Note that the Latin means to form a pool.
1adjectivestagnantStill, and smelling of standing water.
“Mosquitoes breed in the stagnant water of old tyres and ditches.”
2adjectivegrowingNot growing or developing.
“The economy has been stagnant for years, with wages barely rising.”
stagnant is a quality of stillness.
Latin stagnans comes from stagnare, to form a pool of standing water, from stagnum, a pool.
Latin
stagnans
French
stagnant
English, today
stagnant
Built from
From French stagnant, from Latin stagnans, present participle of stagno (“to form a pool of standing water”).
Etymology from Wiktionary, CC BY-SA
Practised in Smell & Taste