Antonyms of adj unthoughtful

1 sense of unthoughtful

Sense 1
unreflective, unthinking, unthoughtful -- (not exhibiting or characterized by careful thought)

INDIRECT (VIA thoughtless) -> thoughtful -- (exhibiting or characterized by careful thought; "a thoughtful paper")

Similarity of adj unthoughtful

1 sense of unthoughtful

Sense 1
unreflective, unthinking, unthoughtful -- (not exhibiting or characterized by careful thought)
       => thoughtless (vs. thoughtful) -- (showing lack of careful thought; "the debate turned into thoughtless bickering")