Green’s Dictionary of Slang

1. characteristic of, or relevant to, drugs or drug-taking.

1907		Lippincott’s Monthly Mag. (Phila.) Feb. 285: Hoppy-eyed an’ full of hash-sheesh [HDAS].
1942		Berrey & Van den Bark Amer. Thes. Sl.
1946		Mezzrow & Wolfe Really the Blues 98: Detroit is really a hoppy town—people must order their opium along with their groceries.

2. smelling of opium.

1959

J.E. Schmidt Narcotics Lingo and Lore.