Also found in: Thesaurus, Medical.
1. Not flowing or moving, and often foul-smelling or stale: stagnant ponds; stagnant air.
2. Showing little or no activity or vitality; inactive or sluggish: a stagnant economy; a stagnant mind.
[Latin stāgnāns, stāgnant-, present participle of stāgnāre, to be stagnant; see stagnate.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.