Green’s Dictionary of Slang

a supposed gangland method of murder; the victim’s feet are dunked in quick-drying concrete and they are then dumped into a river or overboard from a boat, the irremovable weight ensuring that they drown.

1945		J. Archibald ‘Smoke Scream’ in 10-Story Detective Feb. 🌐 To make sure you don’t come up when we toss you in the drink, copper [...] Ever see a concrete negligee, flatfoot?
1965		J.P. Carstairs Concrete Kimono 51: What are you asking for — a concrete kimono?
1975		‘P.B. Yuill’ Hazell and the Three-card Trick (1977) 172: I can’t see you’ll be floating with concrete socks on, baby.
1977		E. Torres Q&A 104: ‘I told him to take a walk. Later he walked off a pier in Brooklyn.’ ‘Homicide?’ Reilly asked. ‘Nah, he was wearin’ concrete drawers’.
1982		J. Sullivan ‘No Greater Love’ Only Fools and Horses [TV script] When we come to pay our last respects to you, you’ll be wearing a concrete overcoat. You’ll be helping to support a flyover on the M26!
1999		Indep. on Sun. Culture 11 July 1: The nearest they’ll get to being hefted into Deptford Creek in a concrete overcoat.
2001		Indep. 14 Feb. 10: Liddle, rather than wearing concrete clogs in a Scottish lake, had taken £5,800 from his firm’s bank account and with it the opportunity for a new life.