1. to undergo or cause a chemical change in which sugar is converted to alcohol by yeast or bacteria
2. to cause or experience excitement, agitation, or unrest

1. a substance that causes fermentation, especially yeast
2. a state of excitement, agitation, or unrest

Examples

• The grapes will ferment into wine over several weeks.
• She added yeast to ferment the bread dough.
• Political tensions began to ferment among the citizens.
• The baker used a sourdough ferment to make the bread.
• The country was in a state of ferment before the revolution.
• Bacteria ferment the milk to create yogurt.
• Social media helped ferment discontent about the new policy.