1. Not exhibiting or characterized by careful thought
   - unreflective, unthoughtful 
2. Without care or thought for others
   - thoughtless, uncaring 
3. Mentally sluggish
   - lumpish, lumpen

1. In a thoughtless manner
   - thoughtlessly, unthinkingly

See also: inconsiderate, stupid, thoughtless

• insertional mutagenesis
• Insessores
• inset
• inshallah
• inshore
• inside
• inside caliper
• inside clinch
• inside information
• inside job
• inside leg
• inside loop
• Inside Passage
• inside track
• inside-out
• insider
• witch-hazel family
• witch-hunt
• witch-hunter
• witchcraft
• witchery
• witches' brew
• witches' broom
• witches' broth
• witches' butter