Untended means not being looked after or cared for. When something is untended, nobody is watching it, maintaining it, or giving it attention.

A garden left untended during a family vacation will quickly fill with weeds, and the tomato plants might wilt without water. An untended campfire is dangerous because sparks could spread without anyone there to control them. A store counter left untended means no employee is there to help customers or watch over the merchandise.

When you tend something, you're actively caring for it: tending a fire, tending sheep, or tending to a scraped knee. Remove that care, and it becomes untended.

You might also hear the similar word unattended, which often emphasizes that something or someone has been left alone: “Never leave young children unattended near water.” The words overlap, but untended especially suggests the absence of ongoing care or maintenance, while unattended simply means no one is present.

Things that need regular attention suffer when left untended: friendships grow distant, skills get rusty, and problems grow larger. An untended garden will take much more work to restore than it would have taken to maintain in the first place.