1. comparative form of sour; more sour in taste
2. comparative form of sour; more unpleasant or bitter in mood or attitude

Examples

• This lemon is sourer than the one I tasted yesterday.
• The milk became sourer after sitting out all day.
• His expression grew sourer as the meeting continued.
• The grapes on this vine are sourer than those on the other side.
• She became sourer about the situation after hearing the news.
• The yogurt tastes sourer than usual today.