Boredom can make you do crazy things, like watching terrible old game shows on television or eating the bag of chocolate chips you find in the freezer. The feeling of being bored or uninterested in what you're doing is boredom.
Everyone experiences boredom sometimes. The feeling that nothing catches your interest, that everything's dull and flat, sums up the state of boredom. Too much time on your hands can result in boredom, and so can the tediousness of doing the same thing over and over again, like a dreary task at a job. The word boredom comes from something called a "boring tool", a kind of drill that works slowly and repetitively; around 1768, bore, meaning "be tiresome," became a popular slang term, and boredom followed.