chalk-sniffer

(noun.) code for somebody who inhales drugs, and is more commonly referenced to a cocaine addict than any other drug that you can nasally ingest.

Krissy: Ever since Jasmine has met Treyvon, she's been off the rails.
Daquan: Treyvon is a chalk-sniffer. The best way to land a hot girl is to get her hooked to blow.