1. ceased to flow or move; became motionless or still
Usage: past tense of stagnate
2. failed to develop, progress, or advance; became inactive or dull
Usage: past tense of stagnate

Examples

• The water stagnated in the old pond during the drought.
• His career stagnated after he refused the promotion.
• The economy stagnated for several years following the recession.
• Without fresh ideas, the company’s growth stagnated.
• The air stagnated in the closed room without ventilation.
• Her skills stagnated because she stopped practicing.
• The negotiations stagnated when neither side would compromise.