(Scotland) A person, typically a young boy or girl, who is hired to run errands and carry goods and messages, especially in large scottish cities and towns in the early 18th century.

(by extension, golf, also attributively) A person hired to assist a golfer by carrying their golf clubs and providing advice.

Alternative spelling of caddy

(intransitive, golf) Chiefly followed by for: to serve as a caddie (noun sense 2) for a golfer.