Green’s Dictionary of Slang

1. (US drugs) prescription cough syrup, containing codeine.

1996		UGK ‘That’s Why I Carry’ 🎵 We got the red drink orange drink purple drink.
2007		UGK ‘Underground Kingz’ 🎵 Trying to sip some’ing too, so nigga pass the purp’.
2008		N.Y. Times 11 Feb. 🌐 Prescription cough syrup — sometimes diluted, and often called ‘drank’ or ‘lean’ or ‘purp’ — is the recreational drug most closely associated with Houston’s fertile hip-hop scene.
2008		The Ampersand 6 Feb. 🌐 It’s about purple stuff/syrup/purple drank/lean, a popular recreational drug concoction which combines cough syrup and (usually) Sprite.
2014		http://www.today.com 23 Jan. 🌐 Also known as ‘purple drank,’ ‘syrup’ and ‘lean,’ sizzurp typically includes Jolly Rancher candy for color and extra sweetness along with soda and prescription-strength cough syrup. The end product is said to provide an instant, euphoric high.
2017		Guardian 17 Nov. 5/1: ‘Pop two cups of purple just to warm up’ [...] ‘Purple’ is a drink made from codeine-based cough syrup.

2. a strain of marijuana that displays purple hairs and deep greens.

2002		E-40 ‘Much’ 🎵 Man, I’m over here on super purp.
2005		High Times 19 May 🌐 [photo caption] God’s Gift a.k.a. Purps from TH Seeds.
2008		R. Price Lush Life 426: Having found three sticky buds of Purp underneath Little Dap’s [etc.] .
2012		Meek Mill ‘Burn Out’ 🎵 My purp strong like it’s lifting weights.