Yes, cooper is a Scrabble word!

Verb

1. Make barrels and casks

Noun

1. United States industrialist who built the first American locomotive; founded Cooper Union in New York City to offer free courses in the arts and sciences (1791-1883)

2. United States film actor noted for his portrayals of strong silent heroes (1901-1961)

3. United States novelist noted for his stories of American Indians and the frontier life (1789-1851)

4. A craftsman who makes or repairs wooden barrels or tubs