Absently
/ˈæbsəntli/
Definition 1 of 1
Pro Tip 1/3Lack of Focus
Used when someone isn't paying full attention to their current activity or surroundings. 
She turned the pages absently, her thoughts elsewhere.
Pro Tip 2/3Unintentional Action
Describes an action done without conscious control or intention, often habitual. 
He absently twirled his pen while lost in thought.
Pro Tip 3/3Subtle Emotion
Conveys a mild, non-intense emotion, not strong detachment or aloofness. 
Her smile was absently polite, not truly engaged.