1. In a thoughtless manner
   "he stared thoughtlessly at the picture"
   - unthinkingly, unthinking 
2. Showing thoughtlessness
   "he treated his parents thoughtlessly"

See also: thoughtless

Antonym: thoughtfully

• considerably
• considerate
• considerately
• considerateness
• consideration
• considered
• consideringly
• consigliere
• consign
• consignee
• consigner
• consignment
• consignor
• consilience
• consist
• consistence
• consistency
• consistent
• consistently
• consistorial
• consistory
• consociate
• consolable
• consolation
• consolation prize