Green’s Dictionary of Slang

Henry VIII n.

also henry
[abbr.]

(drugs) an eighth of an ounce of a drug, e.g. cannabis or cocaine.

[UK]N. Barlay Hooky Gear 152: Least the henry of skunk Duane give me as a kiss-off help a bit.
[US]ONDCP Street Terms 11: Henry VIII — Cocaine.
OnLine Dict. of Playground Sl. 🌐 henry n. Do you want to buy a Henry?, Refers to an eighth of an ounce of hashish, which has always been a popular drug in playgrounds.
[UK]Observer 11 June 9: Would you know what I was talking about if I asked for ‘an ’Enry’ and said, ‘It’s for Percy?’ he asked. ‘It means I want an eighth of an ounce of cannabis for personal use.’.
Twitter 17 June 🌐 SHOUTOUT EVRY1 WALKIN AROUND LOOKING LIKE THEYVE JUST BLAZED A HENRY.