Third-person singular simple present indicative form of stagnate

Inactivity / Being stagnant; being without circulation.

(of water, air, etc) To cease to flow or run. / (of water, air, etc) To be or become foul from standing. / To cease to develop, advance, or change; to become idle.

present participle of stagnate

simple past tense and past participle of stagnate

plural of stagnation

(fluid dynamics) A point in a flow field where the local velocity of the fluid is zero.

plural of stagnation point