1. the quality or state of being interesting; the capacity to hold or attract someone's attention or curiosity
Usage: abstract noun; informal

Examples

• The interestingness of the novel kept me reading late into the night.
• What adds to the interestingness of this historical event is the personal letters that were recently discovered.
• The teacher praised the interestingness of the student's research project.
• The interestingness of the documentary made it worth watching despite its length.
• I was surprised by the interestingness of the topic once I started learning more about it.
• The interestingness of the conversation made the long flight pass quickly.