Green’s Dictionary of Slang

(W.I. Rasta) a friendly term for a fellow Rastafarian.

1980		B. Marley ‘Buffalo Soldier’ 🎵 Sais he was a buffalo soldier, dreadlock rasta [...] Dreadie.
1984		S. Baku ‘One Bad Casa’ in Three Plays I ii: Dreadie, call me in a week.