1. most lacking in taste, style, or quality; most tacky or cheap
Usage: informal
2. most overly sentimental or corny
Usage: informal
3. having the most cheese flavor or containing the most cheese

Examples

• That was the cheesiest pickup line I’ve ever heard.
• The movie had the cheesiest special effects from the 1980s.
• She wore the cheesiest costume to the party.
• The cheesiest pizza on the menu has five different types of cheese.
• His cheesiest smile appeared whenever he wanted something.
• The restaurant serves the cheesiest nachos in town.
• That’s the cheesiest love song ever written.