Green’s Dictionary of Slang

swing, the n.

the gallows.

1816		‘Newgate Melody’ in Morn. Post 17 Apr. 3/4: If the hand of a friend the cord bring, / There will be little pain in the swing.
1821		‘A Real Paddy’ Real Life in Ireland 114: In a few minutes I will get the swing.
1832		Satirist (London) 1 Jan. 5/2: Then some have had their Swing in Kent, / And some at Newgate too.
1885		Bulletin (Sydney) 22 Aug. 6/4: Tom stood it very well for a time, but at last, losing all patience, he poked his head into the cell door and shouted out, ‘Musha, long loife t’ ye, Misthur O’Brien, but wud ye plaze to hurry along wid yer prayers? The jintilmin are getting’ tired waitin’ undernaith yer purty little shwing beyant there.’.