Divider (noun)

1. A device, such as a partition or screen, that separates or divides a space or area.
2. A tool or instrument used to divide or mark off sections or measurements.
3. A person or thing that separates or distinguishes one group or thing from another.

Origin:

From the latin word dividere, meaning to divide.

Examples:

1. The room divider created a sense of privacy in the open-plan living space.
2. I used a ruler and a divider to draw a straight line.
3. The divider between the kitchen and the living room was a half-wall with a built-in bookshelf.
4. The divider in the drawer helped to keep my jewelry organized.
5. The divider in the football field marked the spot for the kickoff.