The Abbey Theatre Playwright crossword solutions are Clifford Odets and Sean O'Casey. Clifford Odets was an American playwright, director, and actor who was a major force in the development of American drama in the 1930s. He is best known for his plays Waiting for Lefty and Awake and Sing. Sean O'Casey was an Irish dramatist and memoirist who wrote about the Dublin working class. His most famous works include Juno and the Paycock and The Plough and the Stars.