"Boredom has at its core the desiring of satisfying engagement but not being able to achieve that," Eastwood said. "And attention is the cognitive process whereby we interface with both the external world and our internal thoughts and feelings. So it falls logically that attention must be at the core of the definition."
Meaninglessness is boring. Boredom can be described as a meaning withdrawal, in analogy with drug withdrawal, as a discomfort that tells us that our need for meaning is not being met.