Green’s Dictionary of Slang

geeze (up) v.

also geese, geez
[geezer n.3 (1); given the date of the root n., Spears, Slang and Jargon of Drugs and Drink (1986), is surely right to suggest ‘this may be much older than the attestations suggest’]

1. to inject narcotics; in cit. 1985 note second sense meaning to stab someone, which is poss. a misinterpretation.

[US]Rigney & Smith Real Bohemia 58: The dissolved drug is drawn up through a needle (the ‘point’) and then injected through the skin (’geezed’).
[US]L. Wolf Voices from the Love Generation 14: If you’re on smack, geezing up in the kitchen, you generate a certain type of energy.
[US]J. Wambaugh Choirboys (1976) 201: When he’s geezing and on the nod.
[US]J. Ellroy Brown’s Requiem 69: I’m gonna geez. I can’t talk to you till I get over these shakes.
[US]T.R. Houser Central Sl. 25: geese To shoot dope in one’s arm. [...] To stab someone.
[US]J. Stahl Permanent Midnight 10: I geezed a speedball.
[US](con. 1964–8) J. Ellroy Cold Six Thousand 101: White horse would work. The niggers craved it. They’d geez up.
[US]J. Stahl ‘Twilight of the Stooges’ in Love Without (2007) 154: I never saw her do anything but cocaine [...] Suzy didn’t geeze, she thought it was low class.
[US]J. Stahl Bad Sex on Speed 33: You were geezing this evil-smelling grit [...] Bathtub crank.
[US]J. Ellroy Widespread Panic 124: They fed a spike. They tied off tourniquets. They geezed.

2. (US drugs) to inject someone else with narcotics or medicine.

[US]J. Stahl Happy Mutant Baby Pills 19: Grandma spanking Grandpa and jabbing the rig in [...] The second his wife of sixty-seven years geezed him, he’d pop a ‘Life Saver.
[US](con. 1962) J. Ellroy Enchanters 46: He geezed them up with his own dope concoctions.

3. to inhale cocaine.

[US]ONDCP Street Terms 10: Geeze — To inhale cocaine.