Possible Clues:

• Dramatist...... O'Neill wrote 'The Iceman Cometh'
• Painter Delacroix
• Writer O'Neill
• . . . . . . Onegin (Tchaikovsky) (6)
• . . . . . . O'Neill was a great American playwright
• O'Neill or Ionesco
• City NW of Crater Lake
• - - O'Neill, American dramatist 1888-1953
• The same two get away from the front - the thug then the fellow
• Great American playwright . . . . . . O'Neill