Green’s Dictionary of Slang

1. (US tramp) to ride on the roof of a freight car.

1894		J. London Tramp Diary in Jack London On the Road (1979) 35: Two of us jumped the palace cars & decked them while the third went underneath on the rods.
1907		J. London Road 38: Only a young and vigorous tramp is able to deck a passenger train.
1917		‘A-No. 1’ From Coast to Coast with Jack London 67: What’re you doing, guys? Decking my train, eh?
1921		P. & T. Casey Gay-cat 189: I grabbed an iron ladder alongside and swung up an’ decked her.
1927		W. Edge Main Stem 17: He would [...] find out the hour of an express departure, and would then lay his plans to ‘deck the cannon-ball on the fly’.
1930		G. Milburn ‘The Dealer Gets It All’ in Hobo’s Hornbook 152: Then Alton he got busy, and produced a fancy briar, / And we crushed the can at midnight, and decked an eastbound flyer.
1937		‘Boxcar Bertha’ Sister of the Road (1975) 25: He managed this by riding the rods and decking the coaches as far as Butte, Montana.

2. (US Und.) to drill through the top of a safe.

1928

J. Callahan Man’s Grim Justice 54: We seldom decked a pete. ‘Decking,’ incidentally, means drilling through the top of the safe.

3. (orig. US teen) to ride a skateboard.

1992

J. Mowry Way Past Cool 14: Gordon snagged his board [...] and decked easily despite his mass.