- not stopping to think; careless
- not given thought; ill-considered; rash
- not considerate of others; inconsiderate
- Rare stupid; senseless
See thoughtless in American Heritage Dictionary 4
- Marked by or showing lack of due thought or care; careless. See Synonyms at careless.
- Inconsiderate; inattentive: a thoughtless remark.
- Lacking thought: The debate turned into thoughtless bickering.
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