1. (n.) The quality of being inadvertent; lack of heedfulness or attentiveness; inattention; negligence; as, many mistakes proceed from inadvertence.

2. (n.) An effect of inattention; a result of carelessness; an oversight, mistake, or fault from negligence.

Lethe Walter Mitty absence of mind absorption abstractedness abstraction bemusement brown study carelessness castle-building daydream daydreamer daydreaming decay of memory depth of thought disregard disregardfulness distraction dream dreaming engrossment fantasy fantasying fit of abstraction flightiness flippancy forgetfulness forgetting forgiveness frivolousness giddiness hazy recollection heedlessness inadvertence inadvertency inattention inattentiveness inconsideration incuriosity indifference inobservance levity lightmindedness mooning moonraking muse musefulness musing muted ecstasy negligence nepenthe nirvana nonobservance obliteration oblivion obliviousness pipe dream pipe-dreaming preoccupation regardlessness reverie shallowness short memory stargazing study superficiality thoughtlessness trance unalertness unawareness unconsciousness unheedfulness unintentiveness unmindfulness unobservance unwariness unwatchfulness waters of oblivion woolgathering