Yes, circle is a Scrabble word!

Verb

1. Travel around something

2. Move in circles

3. Form a circle around

Noun

1. Ellipse in which the two axes are of equal length; a plane curve generated by one point moving at a constant distance from a fixed point

2. An unofficial association of people or groups

3. Something approximating the shape of a circle

4. Movement once around a course

5. A road junction at which traffic streams circularly around a central island

6. Street names for flunitrazepan

7. A curved section or tier of seats in a hall or theater or opera house; usually the first tier above the orchestra

8. Any circular or rotating mechanism