verb

stagnate

STAG-nayt/ˈstæɡneɪt/

To remain still instead of flowing.

Water stagnates in the ditch when leaves block the drain.

A shallow drainage channel has become a stagnant pool behind a blockage: trapped leaves, a continuous film of green algae, and an undisturbed surface contrast with the dry channel beyond the obstruction.

Etymology

Latin stagnare supplies the image of water standing without a current. English stagnate moved from ceasing to flow to ceasing to be active, giving its sense of stalled development or progress.

In context

NOVA PBS Official42:32

… it managed to completely stagnate. So Kamb Ice Stream is really no longer flowing. It's moving at just a few centimeters per year …

Interview: How to Save The “Doomsday Glacier” with Brent Minchew | Particles of Thought

More examples

Without a working pump, water in the fountain stagnates.
The blocked channel allows water to stagnate.
Water has stagnated in this unused pipe for weeks.

Forms

stagnate · stagnates · stagnated · stagnating

stagnant adjective — Standing still rather than flowing.

stagnation noun — The condition of remaining still without flowing.

Similar words

stand: Describes liquid remaining in place, without suggesting deterioration.
pool: Emphasizes liquid gathering in one place rather than ceasing to flow.