Use 'dreamily' to suggest someone is lost in their own thoughts and not focused on the immediate surroundings. He answered the question dreamily, as if he were somewhere else.
Pro Tip 2/3
Romantic Atmosphere
'Dreamily' often implies a sense of romance or longing when describing someone's gaze or actions. The couple danced dreamily, oblivious to the world around them.
Pro Tip 3/3
Abstract Focus
Used to express that someone is thinking about something vague or not immediately clear or practical. She spoke of her future dreamily, without concrete details.