Yes, cube is a Scrabble word!
...and is worth 8 points in Scrabble, and 11 points in Words with Friends
cube
Verb
1. Raise to the third power
2. Cut into cubes
Noun
1. A hexahedron with six equal squares as faces
2. A three-dimensional shape with six square or rectangular sides
3. The product of three equal terms
4. Any of several tropical American woody plants of the genus Lonchocarpus whose roots are used locally as a fish poison and commercially as a source of rotenone
5. A block in the (approximate) shape of a cube
What Scrabble words can I make with the letters in cube?
3 Letter Words
2 Letter Words