stagnation

From stagnate +‎ -ation (suffix denoting an action or process, or its result), Stagnate is derived from stagnāt-, the participial stem of Latin stagnāre, the present active infinitive of stāgnō (“of waters: to cover the land as a lake, to become a pool, to stagnate”), from stāgnum (“body of standing water (lake, swamp, etc.)”) (possibly from Proto-Indo-European *steh₂g- (“to drip; to seep”)) + -ō (suffix forming regular first-conjugation verbs).