American Heritage Dictionary
(1)
Century Dictionary
(3)
GNU Webster's 1913
(1)
WordNet
(1)
Elsewhere on the web
Whether that's due to stupidity, greed (oooh - I might get something for nothing), boredom, accident or simply curiosity (hmm, I've never replied to SPAM before, I wonder what happens).— doggdot.us
First you will experience boredom, then comes an internal psychic violence and anger, much like the experience of zazen, or sitting meditation, as the layers of your mind conditioning peel away.— How to Save the World
They are just the balanced and fair things to help you take off the chain and ball of boredom, and reduce the tuck and nip of your mundane world.
There's a difference between boredom, and the self-indulgent need to constantly tell people what you're doing, regardless of how mundane it may be.— Pajiba

Century Dictionary (1)
Bubble size: how much this word was used in a year
Bubble height: used more or less than expected, vs. all uses evenly distributed
You can expect to see this word about once a week.