Yes, border is a Scrabble word!

Verb

1. Extend on all sides of simultaneously; encircle

2. Form the boundary of; be contiguous to

3. Enclose in or as if in a frame

4. Provide with a border or edge

5. Lie adjacent to another or share a boundary

Noun

1. A line that indicates a boundary

2. The boundary line or the area immediately inside the boundary

3. The boundary of a surface

4. A decorative recessed or relieved surface on an edge

5. A strip forming the outer edge of something