1. Showing lack of careful thought
   "the debate turned into thoughtless bickering" 
2. Without care or thought for others
   "the thoughtless saying of a great princess on being informed that the people had no bread; 'Let them eat cake'"
   - uncaring, unthinking

See also: inconsiderate, thoughtfulness, thoughtlessly, thoughtlessness, unconsidered, unreflective, unthinking, unthoughtful

Antonym: thoughtful

Encyclopedia: Thoughtless

• renascent
• Renata Tebaldi
• rencounter
• rend
• render
• render-set
• renderer
• rendering
• rendezvous
• rending
• rendition
• rendzina
• Rene Antoine Ferchault de Reaumur
• Rene Descartes
• Rene Magritte
• Rene-Robert Cavelier
• renegade
• renegade state
• renege
• renege on
• reneger
• renegotiate
• renegue
• renegue on
• renew