Green’s Dictionary of Slang

1. (drugs) a regular narcotics user.

1949		Monteleone Criminal Sl. (rev. edn) 50: chronic A drug addict.
1959		J.E. Schmidt Narcotics Lingo and Lore 29: Chronic – A narcotic addict who subsists on a stabilized and usually small ration.
1995		L. Stavsky et al. A2Z 20/2: chronic [...] a junkie or any regular drug user.

2. (drugs) the state of being habituated to strong marijuana.

2002

Teen Lingo: The Source for Youth Ministry 🌐 chronic [...] 2. The state of being so addicted to marijuana, that only the ‘chronic’ has any effect anymore.

3. (US campus) a cigarette.

1995

Eble Campus Sl. Apr. 2: chronic – cigarette.

4. (drugs) extra-strong marijuana.

1993		Dr Dre ‘Deeez Nuuuts’ 🎵 It’s back on the track / With big money, big nuts, and a big fat chronic sack.
2000		in Shaw Westsiders 10: There’s nothing wrong with havin’ a bong and fillin the cap with chronic.
2019		C.D. Rosales Word Is Bone [ebook] ‘I got some bomb Humboldt Chronic. None of that Compton niggerweed’.
2020		C. Hiaasen Squeeze Me 146: The full three hundred [dollars] [...] which predictably he blew on chronic.

5. in attrib. use of sense 4.

2013

Guardian On Line 24 Aug. 🌐 On the Colorado chronic scene, rubbish beards and backwards baseball caps seem to be compulsory.

6. (drugs) marijuana mixed with crack cocaine.

2002

‘Touré’ Portable Promised Land (ms.) 155: We Words (My Favorite Things) [...] Product. Crack. Smack. Crank. Chronic. Cess. Stress.

7. see chronicker n. (1)