From Longman Dictionary of Contemporary Englishlivelonglive‧long /ˈlɪvlɒŋ $ -lɒːŋ/ adjective → all the livelong day
Examples from the Corpus
livelong• Just went around in my wrapper all the livelong day, my mama would faint.Origin livelong (1300-1400) lief “dear” ((11-19 centuries)) (from Old English leof) (influenced by → LIVE1) + long 