From what I can Make out it's Canidy, but cursive on bottles can sometimes be hard to decipher.
The bottle is 5 3/8" tall with a sunburst on the bottom. In very tiny letters it says 4oz just above the slug plate.
Found this bit of info.
" Fred S. Cassidy was a pharmacist in Wellfleet, Massachusetts, known for his antique druggist bottles from the late 1800s. These bottles are quite rare and often sought after by collectors. They typically have “FRED S. CASSIDY, WELLFLEET, MASS” embossed on them."