Green’s Dictionary of Slang

(W.I., Jam.) Jamaica; also as adj., Jamaican.

1979		‘Trip to Jam Down’ in P. Ashton et al. Our Lives (1982) 45: It was arranged that my family would all be going to Jam Down on 19th October 1978.
1980		M. Thelwell Harder They Come 368: Every cutter, every seller, every trader, every café, every rum shop — all jam dung.
1981		N. Farki Countryman Karl Black 151: If that man, son of the most high, was in Jam-down, and him not white, him might have to rest in Trench Town.
1983		(con. 1973) T. White Catch a Fire 239: The Wailers were back on top. ‘Dem de joint in jamdung,’ as [...] DJ Don Topping put it.
1991		Tony Rebel ‘Sweet Jamaica’ 🎵 Say what a nice place fi live, sweet Jamdown.
1995		Francis-Jackson Official Dancehall Dict. 28: Jamdung Jamaica.
1997		‘Q’ Deadmeat 146: He’d been living in England for over forty years but he still chatted like he was in Jam Down.
2005		Jamaica Gleaner 19 Nov. 🌐 Ras Pete [...] a man in whom much of Jamdown was displeased.
2016		Jamaica Gleaner 9 May 🌐 Crunch time in Jamdown!