The definition of cheesiest is something that is the most corny, cheap and inauthentic or something that has the strongest cheese flavor.
(adjective)
- When someone dresses up in the most ridiculous 80's costume at the party, this is an example of a person who would be described as having the cheesiest costume.
- When a dip has a stronger cheese flavor than any other dip, this is an example of a dip that would be described as the cheesiest.