1. the quality or state of being stale; lack of freshness
2. the quality of being unoriginal, boring, or lacking in novelty

Examples

• The staleness of the bread made it unsuitable for sandwiches.
• She could smell the staleness in the closed room.
• The staleness of his jokes made the audience restless.
• The movie suffered from the staleness of its plot.
• Opening the windows helped eliminate the staleness in the air.
• The staleness of the debate topics bored the students.
• He complained about the staleness of the crackers.