Green’s Dictionary of Slang

1. (Aus.) a display handkerchief, worn in one’s top jacket pocket [it is worn for ‘show’].

1963		Aus. Women’s Wkly 27 Nov. 18/3: I had produced a stylish linen ‘showie’.
1964		in R. Campbell Mummy, Who is Your Husband? in DSUE (1984).

2. (Aus.) a showman, by ext. generic for a gypsy, a traveller.

1996		J. Byrell Lairs, Urgers & Coat-Tuggers 302: [A] fellow showie in Barry Mawson the singer almost physically forced Holmes into making his maiden visit to a racetrack.
2001		(con. 1945–6) P. Doyle Devil’s Jump (2008) 71: ‘You should watch yourself with that mob [...] The showies.’ I looked at him blankly. ‘Showies?’ He laughed. ‘Show people. Gypsies.’.
2012		W. Keyser ‘Carny Lingo’ in http://goodmagic.com 🌐 Showie — An Australian synonym for ‘carny’.