thought·less 
/ˈθɑ:tləs/ adjective
/ˈθɑ:tləs/ adjective [more thoughtless; most thoughtless] : not showing concern for the needs or feelings of other people : inconsiderate
▪ thoughtless behavior ▪ thoughtless comments ▪ a selfish and thoughtless person — opposite thoughtful
▪ thoughtless behavior ▪ thoughtless comments ▪ a selfish and thoughtless person — opposite thoughtful
— thought·less·ly adverb
▪ “That's stupid,” he said thoughtlessly.
▪ “That's stupid,” he said thoughtlessly.
— thought·less·ness noun [noncount]
