Thoughtless
Part of speech: adjective
Definition: Marked by or showing lack of due thought or care; careless. Inconsiderate, inattentive. Lacking thought or consideration.
Example sentence: A consistent thinker is a thoughtless person, because he conforms to a pattern; he repeats phrases and thinks in a groove.
Inconsiderate
Part of speech: adjective
Definition: Not considerate of others, thoughtless.