Pronunciation: (stag'nāt),[key] —v.i.,-nat•ed, -nat•ing. 1. to cease to run or flow, as water, air, etc.
2. to be or become stale or foul from standing, as a pool of water.
3. to stop developing, growing, progressing, or advancing: My mind is stagnating from too much TV. 4. to be or become sluggish and dull: When the leading lady left, the show started to stagnate.