Thoughtless means acting without considering how your actions might affect others, or doing something without thinking it through. When someone is thoughtless, they're not trying to be mean or hurtful, but they cause problems or hurt feelings because they simply didn't stop to think.

A thoughtless comment might hurt a friend's feelings not because you wanted to be cruel, but because you blurted something out without considering how it would sound. If you loudly discuss your birthday party plans in front of someone who wasn't invited, that's thoughtless. You weren't intentionally being mean, you just weren't thinking about their perspective.

Thoughtless actions often create unnecessary problems. Leaving your backpack in the middle of the hallway is thoughtless because you didn't consider that someone might trip over it. Asking to borrow something and never returning it is thoughtless because you didn't think about the other person needing their own possession back.

The opposite of thoughtless is thoughtful or considerate. A thoughtful person pauses before acting or speaking, asking themselves, “How might this affect others?” Everyone acts thoughtlessly sometimes, especially when we're rushed or distracted. The key is noticing when we've been thoughtless and learning to pause and think more carefully next time.