granddaddy noun
also grandaddy /ˈgrænˌdædi/ plural granddaddies
also grandaddy /ˈgrænˌdædi/ plural granddaddies
Learner's definition of GRANDDADDY
[count] informal
2
: someone or something that is the first or oldest one in a particular area or field祖师爷;老祖宗—
usually + of