1. in a casual, informal manner without much thought or preparation
2. in a way that seems rude or dismissive due to lack of attention or interest

Examples

• She mentioned offhandedly that she was moving to Paris next month.
• He offhandedly dismissed their concerns without really listening.
• The teacher offhandedly suggested they read the next chapter.
• She offhandedly remarked that the movie was boring.
• He answered the question offhandedly while checking his phone.
• The boss offhandedly announced the meeting was canceled.
• She offhandedly agreed to help without thinking it through.