grandaddy
From Longman Dictionary of Contemporary EnglishRelated topics: Familygrandaddygran‧dad‧dy, granddaddy /ˈɡrændædi/ noun (plural grandaddies) [countable] American English informal 1 SSFFAMILYgrandfather2 → the grandaddy of somethingExamples from the Corpusgrandaddy• His grandaddy used to work for three dollars a day.• Plenty of booze and chow round out the celebration, considered the grandaddy of July Fourth blasts.