Green’s Dictionary of Slang

1. (Aus.) a business syndicate.

1900		Bulletin (Sydney) 1 Sept. 28/2: The chances are that inside the next two years the Federal Parliament will have taken over the railways, and be prepared to build the Tas. West Coast lines quicker and on better terms than any syndicate, and to work them at half the fares, and for that reason alone the Great Western ‘cat’ should not receive another penn’orth of encouragement.
1902		Bulletin (Sydney) 16 Aug. 12/1: We had these facts on the evidence of the Melbourne Stock Exchange, [...] of the sweaters and nigger-labor crowd, and of almost every respectable citizen who ever ran a fraudulent bank or floated a ‘cat’ mine, and diddled the poor out of their savings, and then complained of their lack of ‘thrift’.

2. (orig. US) Caterpillar tractor; thus a tractor of any make.

1918		DN V 23: Cat, n. Caterpillar traction engine. Farmers.
1936		in E. Pyle Ernie’s America (1989) 153: I made the next trip with him on the cat. It is an immense machine, with a cat trailer behind it.
1948		Hungry Horse News 24 Sept. 1/3: At the present time they have six ‘cats’ working, and expect to have 30 in operation next spring [DA].
1957		P. Rabe Agreement to Kill (2006) 161: A crew with equipment was still working away from the road, cats and a bucket.
1968		J. Healy Death of an Irish Town 11: The big ‘cat’ and its trailer stopped outside Harrisons.
1978		S. Longstreet Straw Boss (1979) 326: They are still wheelmen in the logging section, but now they drive cats.
2001		S. King Dreamcatcher 164: A snowmobile engine, almost certainly the Arctic Cat.

3. (US, also cat walker) a cat burglar.

[1734		C. Johnson Hist. of Highwaymen &c. 186: Young Boys who climb up to the Tops of the Masts at Sea, with great Activity, and are call’d Cats, or Grumeis, by the Sailors. The Thieves that bear this Name are House-breakers, who make use of a Ladder or Ropes, with Hooks in one End of it, by which they easily ascend to Chamber Windows].
1939		Howsley Argot: Dict. of Und. Sl. 12: cat – a thief who uses no flash or other kind of light.
1971–2		C. Shafer ‘Catheads [...] and Cho-Cho Sticks’ in Abernethy Bounty of Texas (1990) 200: cat walker, n. – nighttime burglar.
1988		J. Healy Grass Arena (1990) 141: ‘What do you do?’ says Chas. ‘I’m a cat.’ ‘A what?’ ‘A cat burglar.’.

4. (drugs) methcathinone.

2001		ONDCP Street Terms 5: Cat — Methcathinone.
2003		Community Counseling and Resource Center 🌐 ‘Designer Drugs’: Methcathinone: Cat.