Green’s Dictionary of Slang

1. (US) of money, counterfeit [note citation in Phrenological Jrnl (Mar. 1872 215/2) of same phrase uses shyst].

1872

Orleans Co. Monitor (Barton, VT) 1 Apr. 2/2: There is a flood of counterfeit money afloat called shysty or Wild Cat which I would adise you not to touch.

2. (orig. US) a general negative, used of situations, objects and primarily people, in which case a degree of arrogance/cockiness is implied.

1873		Home Jrnl (Winchester, TN) 7 Aug. 2/5: We don’t believe in taking the law into hands in such a manner, but the law has become so ‘shysty’ here [...] that people must act for themselves.
1997		Salt-N-Pepa feat. Mad Lion, Queen Latifah ‘Friends’ 🎵 Brand New [album] No time to worry about who likes me, who didn’t invite me / Behind my back callin’ me shysty, that don’t excite me.
2007		Philadelphia Inquirer (PA) 8 Feb. A17/5: ‘It sounds like he’s a little shysty’.

3. (US) tight-fisted, greedy.

1993–2003		Danny Delinquent on Urban Dict. 🌐 shysty Of dubious honesty; greedy, like a shyster. They didn’t give you your money back? That’s hella shysty, dude.
2005		Indianapolis Star 25 Aug. n.p.: I also don’t like dealing with shysty club owners.
2011		Morn. Call (Allentown, PA) Sports 24 July 37/4: ‘It’s not that we think they’re shysty or trying to pull a fast one [...] These guys are phenomenal businessmen’.