Green’s Dictionary of Slang

tripping n.

[trip v.1 (1)]

1. the state of experiencing a drug, usu. hallucinogenic, orig. only of LSD.

[US](con. 1982–6) T. Williams Cocaine Kids (1990) 138: [of cocaine] tripping to get high.
[US]L. Bing Do or Die (1992) 147: I got an uncle who smoked [PCP], and he got to trippin’, tearin’ the house up, takin’ off all his clothes.
[UK]M. Dibdin Dark Spectre (1996) 50: To Vince, time not spent balling, tripping or bopping, preferably all at once, was time wasted.
[UK]N. Griffiths Grits 94: Am a bit weary-a trippin since-a larst time which nirly blew me fuckin ead off.
[UK]E. St Aubyn Mothers Milk 40: This is incredible, it’s like tripping without the drugs.

2. (US black, also tabbing) experiencing unpleasant effects as a result of consuming hallucinogens.

[US]Eble Campus Sl. Oct. 6: tripping – suffering the ill effects of LSD. Also tabbing.

3. emotionally unstable.

[UK]J.J. Connolly Viva La Madness 45: Musta been trippin, soppy tart.