1. [1980s+] (US black) fashionable, chic, ‘with it’.
2. [1980s+] (US black) correct, the real thing.
3. [1980s+] (orig. US black) calm, untroubled, relaxed.
4. [1990s+] (US black) safe.
5. [1980s+] (US black) emotionless, withdrawn, detached.
[1990s+] (US black) one’s home.
[1980s+] (US campus) a metaphorical ‘medicine’ that acts to calm one down; usu. in imper. phr. take a chill pill, relax.