Green’s Dictionary of Slang

(orig. US) a general term of approval, excellent, wonderful; thus constr. with a, an excellent example.

1922		S. Lewis Babbitt 216: The Rev. Dr. John Jennison Drew [...] is a wizard soul-winner.
1932		E. Waugh Black Mischief 277: They [...] righted themselves and stopped dead within a few feet of danger. ‘Wizard show that,’ remarked the pilot.
1945		N. Marsh Died in the Wool (1963) 60: He’d got a wizard of a camera.
1946		G. Gibson Enemy Coast Ahead (1955) 50: God, look at those bags under his eyes; he must have had a wizard time!
1953		A. Buckeridge Jennings’ Diary 241: Isn’t it wizard to think we’re going home in a few hours from now, sir?
1965		J.P. Carstairs Concrete Kimono 110: A perfectly wizard idea.
1979		‘Iceberg Slim’ Airtight Willie and Me 165: The good old days of wizard torsos.
1989		R. Dahl Rhyme Stew (1990) 34: I’ve got a wizard plan.
1999		Guardian Editor 8 Oct. 20: It was absolutely wizard to hear gunfire.
2006		F.X. Toole Pound for Pound 13: Och, paddy, he’s wizard.