1. a gradual increase or accumulation of something
2. the process of preparing for or leading up to something important
3. publicity or promotion designed to create interest or excitement

Examples

• There was a dangerous buildup of gas in the mine.
• The military buildup along the border worried neighboring countries.
• The buildup to the championship game lasted for weeks.
• All the media buildup made the movie seem better than it actually was.
• A buildup of plaque can cause tooth decay.
• The tension buildup before the announcement was unbearable.
• The company’s marketing buildup for the new product was extensive.