Green’s Dictionary of Slang

to delight, to enthral, to please very much.

1924		Variety 24 Dec. 14/5: He doesn’t wow ’em at any time and seems misplaced in the show [OED].
1932		W.R. Burnett Giant Swing 265: ‘Here’s the Kid that went down to the big burg and wowed them’.
1949		Wodehouse Mating Season 11: His sister Corky has been wowing the customers.
1957		G. Kersh Fowlers End (2001) 196: When the film busts during a children’s matinee, this never fails to wow the little bastards.
1967		K. Amis letter 28 Sept. in Leader (2000) 688: Firm title: I WANT IT NOW (it being several things, but chiefly IT). That should wow them.
1971		Wodehouse Much Obliged, Jeeves 119: Apparently he failed to wow the customers at the Chamber of Commerce lunch.
1982		M. Braun Judas Tree (1983) 38: Miss Lola [...] You sure wowed ’em tonight!
1998		Source Nov. 176: Jay accepts, freaking a fancy trick that wows the crowd.
2008		Camden New Journal (London) Rev. 28 Aug. IV: The bejewelled fantasy outfits of dazzling colours and design worn by the Motown girls [...] wowed audiences around the world.
2010		J. Ellroy Hilliker Curse 15: He just slipped Perry Mason a fat retainer. That wowed me.
2015		Mail & Guardian (Johannesburg) 8 Oct. 🌐 Pharrell Williams’s shows [...] wowed crowds.
2021		J. Ellroy Widespread Panic 93: I flashed my Special DA’s Investigator badge at a wowed desk lady.