His unthoughtful remark at the party upset several guests.

His unthoughtfulness in leaving the lights on overnight ended up costing the office hundreds of dollars.

The scientist proposed an unthought-of solution that changed the field.

Late at night she read through her notebook, smiling at the small unthoughts she'd dismissed as too strange to share.

An unthought solution emerged during the meeting and solved a problem we had struggled with for weeks.

She sketched the unthought at the margin of her notebook, hoping to coax a new idea into being.

She unthought the idea as soon as she realized it was harmful.

Her unthoughted reply surprised everyone at the meeting.

He unthoughtfully left his umbrella in the café, and it began to rain an hour later.